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 (
    1231444, 1232132, 2382470, 1231619, 
    1231934, 1232067, 1129861, 1232342, 
    1232255, 1232131, 1231263, 1129864, 
    1231062, 1231061, 1231700, 1231550, 
    2310531, 2382443, 1231689, 1231916, 
    1231554, 1232118, 1232182, 1141555, 
    2615750, 1232128, 2538988, 2382442, 
    1231692, 1232127, 1231275, 2462833, 
    1198910, 1231186, 1162591, 1231272
  ) 
  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 0.00207

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "53.76"
    },
    "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": "46.57",
          "eval_cost": "7.20",
          "prefix_cost": "53.77",
          "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 (1231444,1232132,2382470,1231619,1231934,1232067,1129861,1232342,1232255,1232131,1231263,1129864,1231062,1231061,1231700,1231550,2310531,2382443,1231689,1231916,1231554,1232118,1232182,1141555,2615750,1232128,2538988,2382442,1231692,1232127,1231275,2462833,1198910,1231186,1162591,1231272)) and (`maniamall_cscart`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}

Result