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 (
    5503, 5504, 5163, 5153, 1419, 1420, 1421, 
    3157, 5132, 5133, 5134, 5135, 1452, 
    5161, 1442, 5151, 6734, 6733, 6729, 
    6710, 1721, 1722, 1723, 1724, 1725, 
    1726, 1727, 1728, 1729, 1730, 1731, 
    1732, 1733, 1734, 1735, 1736, 1737, 
    1738, 1739, 1740, 1741, 1742, 1743, 
    1744, 1745, 1746, 1747, 1748, 1749, 
    1750, 1751, 1752, 1753, 1754, 1755, 
    1756, 1757, 1758, 1759, 1760, 1761, 
    1762, 1763, 1764, 1766, 1767, 1768, 
    1769, 3739, 3740, 3741, 3742, 5415, 
    5416, 5417, 5418, 5419, 5420, 5421, 
    5422, 5423, 5424, 5425, 5426, 5427, 
    5428, 5429, 5430, 5431, 5432, 5433, 
    5434, 5435, 5436, 5437, 5438
  ) 
  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 0.00192

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "67.66"
    },
    "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": 97,
        "rows_produced_per_join": 19,
        "filtered": "20.00",
        "index_condition": "(`gaseus`.`cscart_product_prices`.`product_id` in (5503,5504,5163,5153,1419,1420,1421,3157,5132,5133,5134,5135,1452,5161,1442,5151,6734,6733,6729,6710,1721,1722,1723,1724,1725,1726,1727,1728,1729,1730,1731,1732,1733,1734,1735,1736,1737,1738,1739,1740,1741,1742,1743,1744,1745,1746,1747,1748,1749,1750,1751,1752,1753,1754,1755,1756,1757,1758,1759,1760,1761,1762,1763,1764,1766,1767,1768,1769,3739,3740,3741,3742,5415,5416,5417,5418,5419,5420,5421,5422,5423,5424,5425,5426,5427,5428,5429,5430,5431,5432,5433,5434,5435,5436,5437,5438))",
        "cost_info": {
          "read_cost": "65.72",
          "eval_cost": "1.94",
          "prefix_cost": "67.66",
          "data_read_per_join": "465"
        },
        "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)))"
      }
    }
  }
}