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 (
    5474, 5475, 5476, 5477, 5478, 5479, 5480, 
    5481, 5482, 5483, 5484, 5485, 5486, 
    5487, 5488, 5489, 5490, 5491, 5492, 
    5493, 5494, 5495, 5496, 5497, 5498, 
    5499, 5500, 5501, 5502, 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
  ) 
  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 0.00186

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "67.21"
    },
    "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": 96,
        "rows_produced_per_join": 19,
        "filtered": "20.00",
        "index_condition": "(`gaseus`.`cscart_product_prices`.`product_id` in (5474,5475,5476,5477,5478,5479,5480,5481,5482,5483,5484,5485,5486,5487,5488,5489,5490,5491,5492,5493,5494,5495,5496,5497,5498,5499,5500,5501,5502,5503,5504,5163,5153,1419,1420,1421,3157,5132,5133,5134,5135,1452,5161,1442,5151,6734,6733,6729,6710,1721,1722,1723,1724,1725,1726,1727,1728,1729,1730,1731,1732,1733,1734,1735,1736,1737,1738,1739,1740,1741,1742,1743,1744,1745,1746,1747,1748,1749,1750,1751,1752,1753,1754,1755,1756,1757,1758,1759,1760,1761,1762,1763,1764,1766,1767,1768))",
        "cost_info": {
          "read_cost": "65.29",
          "eval_cost": "1.92",
          "prefix_cost": "67.21",
          "data_read_per_join": "460"
        },
        "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)))"
      }
    }
  }
}

Result

product_id price
1419 0.00000000
1420 0.00000000
1421 0.00000000
1442 0.00000000
1452 0.00000000
1721 0.00000000
1722 0.00000000
1723 0.00000000
1724 0.00000000
1725 0.00000000
1726 0.00000000
1727 0.00000000
1728 0.00000000
1729 0.00000000
1730 0.00000000
1731 0.00000000
1732 0.00000000
1733 0.00000000
1734 0.00000000
1735 0.00000000
1736 0.00000000
1737 0.00000000
1738 0.00000000
1739 0.00000000
1740 0.00000000
1741 0.00000000
1742 0.00000000
1743 0.00000000
1744 0.00000000
1745 0.00000000
1746 0.00000000
1747 0.00000000
1748 0.00000000
1749 0.00000000
1750 0.00000000
1751 0.00000000
1752 0.00000000
1753 0.00000000
1754 0.00000000
1755 0.00000000
1756 0.00000000
1757 0.00000000
1758 0.00000000
1759 0.00000000
1760 0.00000000
1761 0.00000000
1762 0.00000000
1763 0.00000000
1764 0.00000000
1766 0.00000000
1767 0.00000000
1768 0.00000000
3157 758.00000000
5132 0.00000000
5133 0.00000000
5134 0.00000000
5135 0.00000000
5151 0.00000000
5153 0.00000000
5161 0.00000000
5163 0.00000000
5474 0.00000000
5475 0.00000000
5476 0.00000000
5477 0.00000000
5478 0.00000000
5479 0.00000000
5480 0.00000000
5481 0.00000000
5482 0.00000000
5483 0.00000000
5484 0.00000000
5485 0.00000000
5486 0.00000000
5487 0.00000000
5488 0.00000000
5489 0.00000000
5490 0.00000000
5491 0.00000000
5492 0.00000000
5493 0.00000000
5494 0.00000000
5495 0.00000000
5496 0.00000000
5497 0.00000000
5498 0.00000000
5499 0.00000000
5500 0.00000000
5501 0.00000000
5502 0.00000000
5503 0.00000000
5504 0.00000000
6710 969.00000000
6729 839.00000000
6733 839.00000000
6734 839.00000000