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 (
    413, 414, 1366, 1367, 1368, 1369, 1370, 
    1371, 1372, 1373, 1374, 1375, 1376, 
    1377, 1378, 1379, 1380, 1381, 1382, 
    1383, 1384, 1385, 1386, 1387, 1388, 
    1389, 1390, 1391, 1392, 3612, 3613, 
    3614, 3615, 4224, 4225, 4226, 4227, 
    4228, 4229, 4230, 5079, 5080, 5081, 
    5082, 5083, 5084, 5085, 5086
  ) 
  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 0.00100

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "34.06"
    },
    "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": 49,
        "rows_produced_per_join": 9,
        "filtered": "20.00",
        "index_condition": "(`gaseus`.`cscart_product_prices`.`product_id` in (413,414,1366,1367,1368,1369,1370,1371,1372,1373,1374,1375,1376,1377,1378,1379,1380,1381,1382,1383,1384,1385,1386,1387,1388,1389,1390,1391,1392,3612,3613,3614,3615,4224,4225,4226,4227,4228,4229,4230,5079,5080,5081,5082,5083,5084,5085,5086))",
        "cost_info": {
          "read_cost": "33.08",
          "eval_cost": "0.98",
          "prefix_cost": "34.06",
          "data_read_per_join": "235"
        },
        "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
413 0.00000000
414 0.00000000
1366 0.00000000
1367 0.00000000
1368 0.00000000
1369 0.00000000
1370 0.00000000
1371 0.00000000
1372 0.00000000
1373 0.00000000
1374 0.00000000
1375 0.00000000
1376 0.00000000
1377 0.00000000
1378 0.00000000
1379 0.00000000
1380 0.00000000
1381 0.00000000
1382 0.00000000
1383 0.00000000
1384 0.00000000
1385 0.00000000
1386 0.00000000
1387 0.00000000
1388 0.00000000
1389 0.00000000
1390 0.00000000
1391 0.00000000
1392 0.00000000
3612 0.00000000
3613 0.00000000
3614 0.00000000
3615 0.00000000
4224 0.00000000
4225 0.00000000
4226 0.00000000
4227 0.00000000
4228 0.00000000
4229 0.00000000
4230 0.00000000
5079 0.00000000
5080 0.00000000
5081 0.00000000
5082 0.00000000
5083 0.00000000
5084 0.00000000
5085 0.00000000
5086 0.00000000