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 (
    428427, 427728, 430953, 401174, 410003, 
    414674, 454104, 409191, 447293, 430593, 
    420431, 401982, 404064, 412826, 455161, 
    400935, 449270, 402248, 406597, 433624, 
    446080, 455290, 427919, 433335, 418284, 
    431392, 437836, 439945, 404692, 455805, 
    438918, 427972, 404415, 421393, 416786, 
    457753, 430469, 450047, 448348, 413081, 
    440081, 460754, 410561, 424471, 455506, 
    456958, 425735, 457743, 410880, 438251, 
    445963, 404705, 455281, 417659, 445013, 
    412981, 419060, 451473, 453502, 410213, 
    422250, 455802, 409880, 440645, 405789, 
    446310, 450867, 406164, 426321, 427080, 
    406770, 408843, 406290, 416109, 428493, 
    452275, 456156, 413521, 438629, 429191, 
    403689, 409425, 459278, 437741, 417942, 
    430408, 433066, 439497, 448196, 426522, 
    448198, 424292, 446957, 426562, 405927, 
    458299
  ) 
  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 0.00339

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.396568849,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_prices",
          "access_type": "range",
          "possible_keys": [
            "usergroup",
            "product_id",
            "lower_limit",
            "usergroup_id"
          ],
          "key": "usergroup",
          "key_length": "9",
          "used_key_parts": ["product_id", "usergroup_id", "lower_limit"],
          "loops": 1,
          "rows": 192,
          "cost": 0.3346388,
          "filtered": 49.99988174,
          "attached_condition": "cscart_product_prices.lower_limit = 1 and cscart_product_prices.product_id in (428427,427728,430953,401174,410003,414674,454104,409191,447293,430593,420431,401982,404064,412826,455161,400935,449270,402248,406597,433624,446080,455290,427919,433335,418284,431392,437836,439945,404692,455805,438918,427972,404415,421393,416786,457753,430469,450047,448348,413081,440081,460754,410561,424471,455506,456958,425735,457743,410880,438251,445963,404705,455281,417659,445013,412981,419060,451473,453502,410213,422250,455802,409880,440645,405789,446310,450867,406164,426321,427080,406770,408843,406290,416109,428493,452275,456156,413521,438629,429191,403689,409425,459278,437741,417942,430408,433066,439497,448196,426522,448198,424292,446957,426562,405927,458299) and cscart_product_prices.usergroup_id in (0,1)"
        }
      }
    ]
  }
}

Result

product_id price
400935 559.56000000
401174 212.33000000
401982 1809.92000000
402248 747.89000000
403689 646.41000000
404064 743.14000000
404415 1755.98000000
404692 1330.06000000
404705 623.88000000
405789 748.19000000
405927 1992.97000000
406164 622.07000000
406290 111.18000000
406597 1933.10000000
406770 1560.14000000
408843 164.19000000
409191 1241.72000000
409425 54.41000000
409880 1439.23000000
410003 1683.77000000
410213 1399.36000000
410561 680.02000000
410880 1357.43000000
412826 856.46000000
412981 50.82000000
413081 1635.38000000
413521 738.80000000
414674 147.76000000
416109 276.60000000
416786 58.42000000
417659 374.45000000
417942 61.30000000
418284 837.32000000
419060 1477.89000000
420431 1999.06000000
421393 1864.24000000
422250 1784.90000000
424292 1523.01000000
424471 1078.02000000
425735 881.80000000
426321 1901.33000000
426522 898.60000000
426562 176.69000000
427080 377.04000000
427728 1193.86000000
427919 1709.55000000
427972 834.60000000
428427 625.65000000
428493 22.75000000
429191 585.51000000
430408 177.90000000
430469 520.86000000
430593 1832.56000000
430953 1938.03000000
431392 1021.52000000
433066 518.10000000
433335 1342.20000000
433624 1891.78000000
437741 724.57000000
437836 1244.90000000
438251 765.39000000
438629 1533.97000000
438918 827.58000000
439497 1324.10000000
439945 735.42000000
440081 1771.53000000
440645 352.20000000
445013 1625.27000000
445963 476.67000000
446080 765.51000000
446310 1396.74000000
446957 1795.71000000
447293 869.96000000
448196 1223.43000000
448198 1425.98000000
448348 1130.55000000
449270 1169.32000000
450047 1865.81000000
450867 244.19000000
451473 179.46000000
452275 577.35000000
453502 1419.76000000
454104 310.11000000
455161 604.55000000
455281 830.68000000
455290 244.59000000
455506 1605.55000000
455802 324.33000000
455805 406.19000000
456156 1982.01000000
456958 225.19000000
457743 1313.37000000
457753 383.17000000
458299 1996.76000000
459278 247.00000000
460754 1598.34000000