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 (
    1828, 1675, 1931, 1544, 1845, 1540, 1512, 
    1525, 1536, 1538, 1937, 1581, 1582, 
    1838, 1938, 1830, 1514, 1835, 1678, 
    1693, 1711, 1699, 1698, 1869, 1834, 
    1833, 1928, 1537, 1539, 1381, 1320, 
    359, 1892, 1898, 1899, 1436, 1411, 1397, 
    1741, 1270, 1376, 1301, 1330, 1215, 
    1439, 1323, 717, 1217, 1343, 1338, 1337, 
    1174, 1486, 718, 1339, 1417, 341, 1324, 
    1275, 1216, 1458, 819, 1460, 1464, 1455, 
    1450, 1382, 1385, 1383, 1386, 25, 1758, 
    1757, 1734, 1176, 1201, 1191, 1182, 
    1825, 1824, 1821, 1761, 1823, 1822, 
    1459, 1477, 1193, 1546, 1254, 1684, 
    1379, 1378, 701, 699, 711, 703
  ) 
  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 0.00301

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_prices",
      "access_type": "range",
      "possible_keys": ["usergroup", "product_id", "lower_limit", "usergroup_id"],
      "key": "product_id",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 104,
      "filtered": 19.59183121,
      "index_condition": "cscart_product_prices.product_id in (1828,1675,1931,1544,1845,1540,1512,1525,1536,1538,1937,1581,1582,1838,1938,1830,1514,1835,1678,1693,1711,1699,1698,1869,1834,1833,1928,1537,1539,1381,1320,359,1892,1898,1899,1436,1411,1397,1741,1270,1376,1301,1330,1215,1439,1323,717,1217,1343,1338,1337,1174,1486,718,1339,1417,341,1324,1275,1216,1458,819,1460,1464,1455,1450,1382,1385,1383,1386,25,1758,1757,1734,1176,1201,1191,1182,1825,1824,1821,1761,1823,1822,1459,1477,1193,1546,1254,1684,1379,1378,701,699,711,703)",
      "attached_condition": "cscart_product_prices.lower_limit = 1 and cscart_product_prices.usergroup_id in (0,1)"
    }
  }
}

Result

product_id price
25 0.00000000
341 122000.00000000
359 155000.00000000
699 103000.00000000
701 113000.00000000
703 113000.00000000
711 110000.00000000
717 118000.00000000
718 0.00000000
819 182000.00000000
1174 91000.00000000
1176 83000.00000000
1182 65000.00000000
1191 83000.00000000
1193 150000.00000000
1201 65000.00000000
1215 0.00000000
1216 88000.00000000
1217 122000.00000000
1254 26000.00000000
1270 140000.00000000
1275 0.00000000
1301 63000.00000000
1320 22000.00000000
1323 110000.00000000
1324 116000.00000000
1330 122000.00000000
1337 88000.00000000
1338 88000.00000000
1339 100000.00000000
1343 116000.00000000
1376 25000.00000000
1378 12000.00000000
1379 12000.00000000
1381 30000.00000000
1382 11000.00000000
1383 11000.00000000
1385 9000.00000000
1386 11000.00000000
1397 34000.00000000
1411 22000.00000000
1417 122000.00000000
1436 22500.00000000
1439 60000.00000000
1450 47000.00000000
1455 47000.00000000
1458 45000.00000000
1459 0.00000000
1460 46000.00000000
1464 0.00000000
1477 100000.00000000
1486 118000.00000000
1512 28000.00000000
1514 34000.00000000
1525 28000.00000000
1536 45000.00000000
1537 30000.00000000
1538 48000.00000000
1539 32000.00000000
1540 42000.00000000
1544 28000.00000000
1546 10500.00000000
1581 0.00000000
1582 0.00000000
1675 0.00000000
1678 39000.00000000
1684 19167.00000000
1693 35000.00000000
1698 35000.00000000
1699 40000.00000000
1711 40000.00000000
1734 14500.00000000
1741 78000.00000000
1757 14500.00000000
1758 14500.00000000
1761 83000.00000000
1821 64000.00000000
1822 60000.00000000
1823 44000.00000000
1824 44000.00000000
1825 83000.00000000
1828 36000.00000000
1830 26000.00000000
1833 14000.00000000
1834 14000.00000000
1835 33000.00000000
1838 0.00000000
1845 33000.00000000
1869 28000.00000000
1892 145000.00000000
1898 0.00000000
1899 0.00000000
1928 23000.00000000
1931 23000.00000000
1937 23000.00000000
1938 22500.00000000