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 (
    10933, 12728, 10947, 10937, 10939, 10941, 
    12734, 12733, 10946, 10931, 12738, 
    12736, 10953, 10949, 3383, 10944, 13063, 
    10938, 10951, 11639, 13224, 10950, 
    10952, 12739
  ) 
  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 0.00085

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "16.81"
    },
    "grouping_operation": {
      "using_filesort": false,
      "table": {
        "table_name": "cscart_product_prices",
        "access_type": "range",
        "possible_keys": [
          "usergroup",
          "product_id",
          "lower_limit",
          "usergroup_id"
        ],
        "key": "product_id",
        "used_key_parts": [
          "product_id"
        ],
        "key_length": "3",
        "rows_examined_per_scan": 24,
        "rows_produced_per_join": 3,
        "filtered": "14.40",
        "index_condition": "(`dev_yourmart_co_bw`.`cscart_product_prices`.`product_id` in (10933,12728,10947,10937,10939,10941,12734,12733,10946,10931,12738,12736,10953,10949,3383,10944,13063,10938,10951,11639,13224,10950,10952,12739))",
        "cost_info": {
          "read_cost": "16.46",
          "eval_cost": "0.35",
          "prefix_cost": "16.81",
          "data_read_per_join": "82"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`dev_yourmart_co_bw`.`cscart_product_prices`.`lower_limit` = 1) and (`dev_yourmart_co_bw`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}