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 (
    430995, 431290, 431004, 431087, 430983, 
    431071, 431231, 431405, 431497, 431381, 
    431411, 431017, 431182, 431274, 431434, 
    430686, 430974, 431045, 431175, 430765, 
    430785, 431001, 431494, 431495, 430762, 
    430965, 431403, 431465, 381710, 430963, 
    431002, 431025, 431240, 431329, 381707, 
    430755, 430964, 430966, 431457, 430630, 
    430752, 430773, 431304, 431284, 431425, 
    431328, 430711, 430961, 431235, 431343, 
    431362, 431422, 431498, 431505, 431079, 
    431355, 431394, 431408, 431243, 431260, 
    431383, 431407, 430759, 431015, 431283, 
    431488, 430669, 430700, 430943, 430971, 
    431105, 431152, 431340, 431352, 431409, 
    430944, 431018, 431057, 431069, 431217, 
    431337, 430705, 430929, 430978, 431030, 
    431419, 430717, 430781, 431311, 431346, 
    431427, 435510, 430938, 430956, 431302, 
    431482, 431500, 431415, 431453, 430732
  ) 
  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 0.00162

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "280.31"
    },
    "grouping_operation": {
      "using_filesort": false,
      "table": {
        "table_name": "cscart_product_prices",
        "access_type": "range",
        "possible_keys": [
          "usergroup",
          "product_id",
          "lower_limit",
          "usergroup_id"
        ],
        "key": "usergroup",
        "used_key_parts": [
          "product_id",
          "usergroup_id",
          "lower_limit"
        ],
        "key_length": "9",
        "rows_examined_per_scan": 200,
        "rows_produced_per_join": 200,
        "filtered": "100.00",
        "cost_info": {
          "read_cost": "240.31",
          "eval_cost": "40.00",
          "prefix_cost": "280.31",
          "data_read_per_join": "12K"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`webmarco`.`cscart_product_prices`.`lower_limit` = 1) and (`webmarco`.`cscart_product_prices`.`product_id` in (430995,431290,431004,431087,430983,431071,431231,431405,431497,431381,431411,431017,431182,431274,431434,430686,430974,431045,431175,430765,430785,431001,431494,431495,430762,430965,431403,431465,381710,430963,431002,431025,431240,431329,381707,430755,430964,430966,431457,430630,430752,430773,431304,431284,431425,431328,430711,430961,431235,431343,431362,431422,431498,431505,431079,431355,431394,431408,431243,431260,431383,431407,430759,431015,431283,431488,430669,430700,430943,430971,431105,431152,431340,431352,431409,430944,431018,431057,431069,431217,431337,430705,430929,430978,431030,431419,430717,430781,431311,431346,431427,435510,430938,430956,431302,431482,431500,431415,431453,430732)) and (`webmarco`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}

Result

product_id price
381707 50.00000000
381710 60.00000000
430630 25.50000000
430669 31.50000000
430686 29.90000000
430700 29.90000000
430705 29.90000000
430711 29.90000000
430717 29.90000000
430732 31.50000000
430752 31.50000000
430755 31.50000000
430759 34.50000000
430762 34.50000000
430765 34.50000000
430773 34.50000000
430781 34.50000000
430785 34.50000000
430929 31.50000000
430938 31.50000000
430943 31.50000000
430944 31.50000000
430956 31.50000000
430961 31.50000000
430963 31.50000000
430964 31.50000000
430965 31.50000000
430966 31.50000000
430971 31.50000000
430974 31.50000000
430978 31.50000000
430983 31.50000000
430995 31.50000000
431001 31.50000000
431002 31.50000000
431004 31.50000000
431015 31.50000000
431017 31.50000000
431018 31.50000000
431025 31.50000000
431030 31.50000000
431045 29.90000000
431057 29.90000000
431069 29.90000000
431071 29.90000000
431079 26.50000000
431087 28.50000000
431105 31.50000000
431152 31.50000000
431175 26.90000000
431182 26.90000000
431217 29.90000000
431231 31.50000000
431235 31.50000000
431240 31.50000000
431243 31.50000000
431260 36.50000000
431274 36.50000000
431283 36.50000000
431284 36.50000000
431290 36.50000000
431302 45.50000000
431304 45.50000000
431311 45.50000000
431328 67.90000000
431329 67.90000000
431337 67.90000000
431340 40.90000000
431343 40.90000000
431346 40.90000000
431352 40.90000000
431355 40.90000000
431362 49.90000000
431381 45.50000000
431383 45.50000000
431394 49.90000000
431403 49.90000000
431405 49.90000000
431407 49.90000000
431408 49.90000000
431409 49.90000000
431411 49.90000000
431415 49.90000000
431419 58.90000000
431422 58.90000000
431425 58.90000000
431427 58.90000000
431434 34.50000000
431453 29.90000000
431457 29.90000000
431465 31.50000000
431482 34.50000000
431488 34.50000000
431494 34.50000000
431495 34.50000000
431497 34.50000000
431498 34.50000000
431500 73.90000000
431505 58.90000000
435510 0.00000000