SELECT 
  SQL_CALC_FOUND_ROWS products.product_id, 
  IF(
    shared_descr.product_id IS NOT NULL, 
    shared_descr.product, descr1.product
  ) as product, 
  stoc_intern, 
  pret_achizitie, 
  pret_revanzator, 
  gestiune 
FROM 
  cscart_products as products 
  LEFT JOIN cscart_product_options_inventory as inventory ON inventory.product_id = products.product_id 
  LEFT JOIN cscart_product_descriptions as descr1 ON descr1.product_id = products.product_id 
  AND descr1.lang_code = 'ro' 
  LEFT JOIN cscart_product_prices as prices ON prices.product_id = products.product_id 
  AND prices.lower_limit = 1 
  INNER JOIN cscart_products_categories as products_categories ON products_categories.product_id = products.product_id 
  INNER JOIN cscart_categories ON cscart_categories.category_id = products_categories.category_id 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  LEFT JOIN cscart_ult_product_descriptions shared_descr ON shared_descr.product_id = products.product_id 
  AND shared_descr.company_id = 1 
  AND shared_descr.lang_code = 'ro' 
  LEFT JOIN cscart_product_popularity as popularity ON popularity.product_id = products.product_id 
WHERE 
  1 
  AND cscart_categories.category_id IN (6765) 
  AND cscart_categories.company_id = 1 
  AND (
    CASE products.tracking WHEN 'O' THEN inventory.amount > 0 WHEN 'B' THEN products.amount > 0 ELSE 1 END
  ) 
  AND (
    products.usergroup_ids = '' 
    OR FIND_IN_SET(0, products.usergroup_ids) 
    OR FIND_IN_SET(1, products.usergroup_ids)
  ) 
  AND products.status IN ('A') 
  AND prices.usergroup_id IN (0, 0, 1) 
GROUP BY 
  products.product_id 
ORDER BY 
  popularity.total desc, 
  product_id ASC 
LIMIT 
  0, 32

Query time 0.00588

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "38.65"
    },
    "ordering_operation": {
      "using_filesort": true,
      "grouping_operation": {
        "using_temporary_table": true,
        "using_filesort": false,
        "nested_loop": [
          {
            "table": {
              "table_name": "inventory",
              "access_type": "system",
              "possible_keys": [
                "pc"
              ],
              "rows_examined_per_scan": 0,
              "rows_produced_per_join": 1,
              "filtered": "0.00",
              "const_row_not_found": true,
              "cost_info": {
                "read_cost": "0.00",
                "eval_cost": "0.10",
                "prefix_cost": "0.00",
                "data_read_per_join": "880"
              },
              "used_columns": [
                "product_id",
                "amount"
              ]
            }
          },
          {
            "table": {
              "table_name": "cscart_categories",
              "access_type": "const",
              "possible_keys": [
                "PRIMARY",
                "c_status",
                "p_category_id"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "category_id"
              ],
              "key_length": "3",
              "ref": [
                "const"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 1,
              "filtered": "100.00",
              "cost_info": {
                "read_cost": "0.00",
                "eval_cost": "0.10",
                "prefix_cost": "0.00",
                "data_read_per_join": "2K"
              },
              "used_columns": [
                "category_id",
                "company_id",
                "usergroup_ids",
                "status"
              ]
            }
          },
          {
            "table": {
              "table_name": "products_categories",
              "access_type": "ref",
              "possible_keys": [
                "PRIMARY",
                "pt"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "category_id"
              ],
              "key_length": "3",
              "ref": [
                "const"
              ],
              "rows_examined_per_scan": 142,
              "rows_produced_per_join": 142,
              "filtered": "100.00",
              "using_index": true,
              "cost_info": {
                "read_cost": "1.20",
                "eval_cost": "14.20",
                "prefix_cost": "15.40",
                "data_read_per_join": "2K"
              },
              "used_columns": [
                "product_id",
                "category_id"
              ]
            }
          },
          {
            "table": {
              "table_name": "products",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY",
                "status"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "product_id"
              ],
              "key_length": "3",
              "ref": [
                "maniamall_cscart.products_categories.product_id"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 7,
              "filtered": "5.00",
              "cost_info": {
                "read_cost": "0.00",
                "eval_cost": "0.71",
                "prefix_cost": "29.60",
                "data_read_per_join": "31K"
              },
              "used_columns": [
                "product_id",
                "status",
                "amount",
                "usergroup_ids",
                "tracking",
                "stoc_intern",
                "pret_achizitie",
                "pret_revanzator",
                "gestiune"
              ],
              "attached_condition": "((0 <> (case `maniamall_cscart`.`products`.`tracking` when 'O' then <cache>((NULL > 0)) when 'B' then (`maniamall_cscart`.`products`.`amount` > 0) else 1 end)) and ((`maniamall_cscart`.`products`.`usergroup_ids` = '') or (0 <> find_in_set(0,`maniamall_cscart`.`products`.`usergroup_ids`)) or (0 <> find_in_set(1,`maniamall_cscart`.`products`.`usergroup_ids`))) and (`maniamall_cscart`.`products`.`status` = 'A'))"
            }
          },
          {
            "table": {
              "table_name": "shared_descr",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY",
                "product_id",
                "company_id"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "product_id",
                "lang_code",
                "company_id"
              ],
              "key_length": "13",
              "ref": [
                "maniamall_cscart.products_categories.product_id",
                "const",
                "const"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 7,
              "filtered": "100.00",
              "cost_info": {
                "read_cost": "0.00",
                "eval_cost": "0.71",
                "prefix_cost": "30.31",
                "data_read_per_join": "27K"
              },
              "used_columns": [
                "product_id",
                "lang_code",
                "company_id",
                "product"
              ]
            }
          },
          {
            "table": {
              "table_name": "descr1",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY",
                "product_id"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "product_id",
                "lang_code"
              ],
              "key_length": "9",
              "ref": [
                "maniamall_cscart.products_categories.product_id",
                "const"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 7,
              "filtered": "100.00",
              "cost_info": {
                "read_cost": "0.00",
                "eval_cost": "0.71",
                "prefix_cost": "31.02",
                "data_read_per_join": "27K"
              },
              "used_columns": [
                "product_id",
                "lang_code",
                "product"
              ]
            }
          },
          {
            "table": {
              "table_name": "popularity",
              "access_type": "eq_ref",
              "possible_keys": [
                "PRIMARY",
                "total"
              ],
              "key": "PRIMARY",
              "used_key_parts": [
                "product_id"
              ],
              "key_length": "3",
              "ref": [
                "maniamall_cscart.products_categories.product_id"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 7,
              "filtered": "100.00",
              "cost_info": {
                "read_cost": "0.00",
                "eval_cost": "0.71",
                "prefix_cost": "31.73",
                "data_read_per_join": "227"
              },
              "used_columns": [
                "product_id",
                "total"
              ]
            }
          },
          {
            "table": {
              "table_name": "prices",
              "access_type": "ref",
              "possible_keys": [
                "usergroup",
                "product_id",
                "lower_limit",
                "usergroup_id"
              ],
              "key": "lower_limit",
              "used_key_parts": [
                "lower_limit",
                "product_id"
              ],
              "key_length": "6",
              "ref": [
                "const",
                "maniamall_cscart.products_categories.product_id"
              ],
              "rows_examined_per_scan": 1,
              "rows_produced_per_join": 3,
              "filtered": "50.00",
              "using_index": true,
              "cost_info": {
                "read_cost": "6.21",
                "eval_cost": "0.36",
                "prefix_cost": "38.65",
                "data_read_per_join": "85"
              },
              "used_columns": [
                "product_id",
                "lower_limit",
                "usergroup_id"
              ],
              "attached_condition": "(`maniamall_cscart`.`prices`.`usergroup_id` in (0,0,1))"
            }
          }
        ]
      }
    }
  }
}

Result

product_id product stoc_intern pret_achizitie pret_revanzator gestiune
522515 Proiector Laser LED Tip Shower 3D Metal Interior/Exterior, 24 Efecte de Lumini Miscatoare si Telecomanda -99 118.73 124.00 Y
897045 Instalatie luminoasa LED de Craciun, 300 led-uri, cu 8 functii, 3m, albastru -99 41.21 41.40 Y
1302501 Instalatie luminoasa LED de Craciun, 20 led-uri, lumina alb rece, 2m, 2x baterii AA -99 3.23 3.88 Y
1302521 Instalatie luminoasa LED de Craciun, 300 led-uri, cu 8 functii, albastru + roz, 3m, 220V -99 41.02 46.26 Y
1429472 Instalatie Tip Furtun Luminos LED pentru Craciun, Lumina Albastra, Exterior Interior, Lungime 20m, 480 LED-uri -99 56.68 68.01 Y
1302511 Instalatie decorativa de Craciun LED, 20 becuri bulb cu 100 led-uri, lumina alb rece, 4m -99 29.60 33.38 Y
1447395 Instalatie de Craciun tip perdea cu franjuri simetrici, model Stelute, 136 LED-uri, 8 moduri iluminare, alb cald -99 47.12 53.13 Y
1302499 Instalatie decorativa LED de Craciun, 20 led-uri, lumina calda, 2m, 3x baterii LR44 -99 5.22 5.89 Y
1447392 Instalatie de Craciun tip perdea cu franjuri inegali, model Stelute, 108 LED-uri, alb cald -99 31.95 36.02 Y
1302514 Instalatie luminoasa LED de Craciun, 100 led-uri, lumina alb rece, 3m, 3x baterii AA -99 10.97 13.16 Y
1302584 Instalatie luminoasa LED de Craciun, 10 led-uri, cu 2 programe, culoare rosu, Alimentat cu baterii 2xAA -99 2.13 2.43 Y
1302515 Instalatie decorativa tip bulb de Craciun LED, 30 becuri bulb cu 150 led-uri, lumina alb rece, 6m -99 49.19 55.48 Y
1447394 Instalatie de Craciun tip perdea cu franjuri simetrici, model Stelute, 136 LED-uri, 8 moduri iluminare, multicolor -99 47.12 53.13 Y
1902970 Instalatie luminoasa model stelute cu 136 LED-uri, pentru Craciun, tip Perdea, cu telecomanda, 2m, multicolor -99 67.09 80.51 Y
1902969 Instalatie luminoasa model stelute cu 136 LED-uri, pentru Craciun, tip Perdea, cu telecomanda, 2m, alb cald -99 67.09 80.51 Y
1902971 Instalatie luminoasa model stelute cu 180 LED-uri, pentru Craciun, tip Perdea, lungime 2m, alb rece/albastru -99 81.00 97.20 Y
1902965 Instalatie luminoasa model stelute cu 92 LED-uri, pentru Craciun, tip Perdea, lungime 2m, alb rece -99 49.93 59.91 Y
1902972 Instalatie luminoasa LED de Craciun, cu 10 led-uri, alb rece, 90 cm, 2xAA -99 2.91 3.49 Y
1902958 Instalatie luminoasa decorativa cu 200 LED-uri, pentru Craciun, tip Perdea, lungime 8m, 220V, multicolor -99 59.94 71.92 Y
1902988 Instalatie luminoasa decorativa Angel Hair, cu 15 siruri LED, 300 led-uri, lungime 2m, 220V, albastru -99 29.68 35.61 Y
1902974 Instalatie luminoasa LED de Craciun, cu 10 led-uri, albastru, 90 cm, 2xAA -99 2.91 3.49 Y
1902975 Instalatie luminoasa LED de Craciun, cu 20 led-uri, alb rece, 1.9 m, 3xLR44 -99 5.18 6.21 Y
1902955 Instalatie luminoasa decorativa cu 200 LED-uri, pentru Craciun, tip Perdea, lungime 8m, 220V, albastru -99 59.94 71.92 Y