SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '', 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description, 
  cscart_product_descriptions.meta_keywords, 
  cscart_product_descriptions.meta_description, 
  cscart_product_descriptions.search_words, 
  cscart_product_descriptions.promo_text 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    1587021, 435102, 796340, 2045191, 2071779, 
    1395208, 1080125, 1717796, 1717787, 
    1717795, 1395206, 1717793, 1717794, 
    2055664, 2055661, 2045209, 2045210, 
    2045195, 2045188, 2045197, 2071769, 
    2071771, 2071772, 1770704, 1483807, 
    1700015
  ) 
  AND cscart_product_descriptions.lang_code = 'ro'

Query time 0.00117

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "31.22"
    },
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 26,
      "rows_produced_per_join": 26,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "28.62",
        "eval_cost": "2.60",
        "prefix_cost": "31.22",
        "data_read_per_join": "99K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description",
        "meta_keywords",
        "meta_description",
        "search_words",
        "promo_text"
      ],
      "attached_condition": "((`maniamall_cscart`.`cscart_product_descriptions`.`product_id` in (1587021,435102,796340,2045191,2071779,1395208,1080125,1717796,1717787,1717795,1395206,1717793,1717794,2055664,2055661,2045209,2045210,2045195,2045188,2045197,2071769,2071771,2071772,1770704,1483807,1700015)) and (`maniamall_cscart`.`cscart_product_descriptions`.`lang_code` = 'ro'))"
    }
  }
}

Result