SELECT 
  cscart_product_prices.product_id, 
  MIN(
    IF(
      cscart_product_prices.percentage_discount = 0, 
      cscart_product_prices.price, 
      cscart_product_prices.price - (
        cscart_product_prices.price * cscart_product_prices.percentage_discount
      )/ 100
    )
  ) AS price 
FROM 
  cscart_product_prices 
WHERE 
  cscart_product_prices.product_id IN (
    612280, 1088508, 1120145, 695183, 600012, 
    614835, 696950, 866417, 528611, 1051364, 
    1434961, 697334, 696523, 1232966, 
    621062, 1025514, 1233023, 694679, 
    591502, 791890, 992022, 991893, 698251, 
    695177, 697198, 822677, 1232947, 1233001, 
    615074, 866379, 1232999, 620876, 698264, 
    1373435, 695006, 1233004
  ) 
  AND cscart_product_prices.lower_limit = 1 
  AND cscart_product_prices.usergroup_id IN (0, 1) 
GROUP BY 
  cscart_product_prices.product_id

Query time 0.00348

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "79.60"
    },
    "grouping_operation": {
      "using_filesort": false,
      "table": {
        "table_name": "cscart_product_prices",
        "access_type": "range",
        "possible_keys": [
          "usergroup",
          "product_id",
          "lower_limit",
          "usergroup_id"
        ],
        "key": "usergroup",
        "used_key_parts": [
          "product_id",
          "usergroup_id",
          "lower_limit"
        ],
        "key_length": "9",
        "rows_examined_per_scan": 72,
        "rows_produced_per_join": 72,
        "filtered": "100.00",
        "cost_info": {
          "read_cost": "72.40",
          "eval_cost": "7.20",
          "prefix_cost": "79.60",
          "data_read_per_join": "1K"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`maniamall_cscart`.`cscart_product_prices`.`lower_limit` = 1) and (`maniamall_cscart`.`cscart_product_prices`.`product_id` in (612280,1088508,1120145,695183,600012,614835,696950,866417,528611,1051364,1434961,697334,696523,1232966,621062,1025514,1233023,694679,591502,791890,992022,991893,698251,695177,697198,822677,1232947,1233001,615074,866379,1232999,620876,698264,1373435,695006,1233004)) and (`maniamall_cscart`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}

Result