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 (
    514, 1505, 1506, 1507, 1508, 1509, 1510, 
    1511, 1512, 1513, 1514, 1515, 1516, 
    1526, 1527, 1528, 1529, 1530, 1531, 
    1532, 1533, 1534, 1535, 1536, 3675, 
    3727, 3728, 3730, 3731, 5210, 5211, 
    5212, 5213, 5214, 5215, 5216, 5217, 
    5218, 5219, 5228, 5229, 5230, 5231, 
    5232, 5233, 5234, 5235, 5236, 7496, 
    7497, 7500, 7501, 7506, 7507, 7528, 
    7529
  ) 
  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 0.00162

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "39.21"
    },
    "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": 56,
        "rows_produced_per_join": 11,
        "filtered": "20.00",
        "index_condition": "(`gaseus`.`cscart_product_prices`.`product_id` in (514,1505,1506,1507,1508,1509,1510,1511,1512,1513,1514,1515,1516,1526,1527,1528,1529,1530,1531,1532,1533,1534,1535,1536,3675,3727,3728,3730,3731,5210,5211,5212,5213,5214,5215,5216,5217,5218,5219,5228,5229,5230,5231,5232,5233,5234,5235,5236,7496,7497,7500,7501,7506,7507,7528,7529))",
        "cost_info": {
          "read_cost": "38.09",
          "eval_cost": "1.12",
          "prefix_cost": "39.21",
          "data_read_per_join": "268"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`gaseus`.`cscart_product_prices`.`lower_limit` = 1) and (`gaseus`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}