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 (
    4570, 1615, 2228, 2593, 3743, 4567, 3112, 
    2441, 2877, 2938, 3944, 4598, 4752, 
    5250, 7616, 5919, 3569, 5817, 3033, 
    5923, 4503, 3104, 4138, 2177, 2942, 
    3664, 5936, 3126, 3370, 7293, 2203, 
    2618, 2788, 4225, 5837, 7279, 7617, 
    2649, 7620, 855
  ) 
  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 0.00154

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 (4570,1615,2228,2593,3743,4567,3112,2441,2877,2938,3944,4598,4752,5250,7616,5919,3569,5817,3033,5923,4503,3104,4138,2177,2942,3664,5936,3126,3370,7293,2203,2618,2788,4225,5837,7279,7617,2649,7620,855))",
        "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)))"
      }
    }
  }
}

Result

product_id price
855 330000.00000000
1615 173000.00000000
2177 15000.00000000
2203 20000.00000000
2228 19000.00000000
2441 1325000.00000000
2593 30000.00000000
2618 46000.00000000
2649 5199000.00000000
2788 290000.00000000
2877 74000.00000000
2938 37000.00000000
2942 45000.00000000
3033 652500.00000000
3104 102000.00000000
3112 171000.00000000
3126 25000.00000000
3370 46000.00000000
3569 1580000.00000000
3664 5000.00000000
3743 6000.00000000
3944 60000.00000000
4138 78000.00000000
4225 45000.00000000
4503 165000.00000000
4567 499000.00000000
4570 1475000.00000000
4598 500000.00000000
4752 738000.00000000
5250 1170000.00000000
5817 1422000.00000000
5837 396000.00000000
5919 108000.00000000
5923 154000.00000000
5936 15000.00000000
7279 2315000.00000000
7293 290000.00000000
7616 750000.00000000
7617 450000.00000000
7620 395000.00000000