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 (
    1572, 1574, 1592, 4974, 2399, 1576, 1665, 
    1586, 5277, 1593, 5899, 5640, 2201, 
    5934, 5939, 3929, 5918, 1562, 5284, 
    5376, 4193, 1571, 5287, 3226, 5281, 
    3218, 5397, 4995, 5270, 2393, 3464, 
    1575, 5278, 5187, 5549, 3935, 1588, 
    1563, 1570, 3826
  ) 
  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 0.00320

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "28.01"
    },
    "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": 40,
        "rows_produced_per_join": 7,
        "filtered": "19.99",
        "index_condition": "(`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_prices`.`product_id` in (1572,1574,1592,4974,2399,1576,1665,1586,5277,1593,5899,5640,2201,5934,5939,3929,5918,1562,5284,5376,4193,1571,5287,3226,5281,3218,5397,4995,5270,2393,3464,1575,5278,5187,5549,3935,1588,1563,1570,3826))",
        "cost_info": {
          "read_cost": "27.21",
          "eval_cost": "0.80",
          "prefix_cost": "28.01",
          "data_read_per_join": "191"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_prices`.`lower_limit` = 1) and (`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}