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 (
    74, 1161, 75, 374, 800, 1136, 224, 795, 
    1839, 797, 798, 1409, 367, 1393, 484, 
    445, 157, 388, 585, 241, 629, 590, 860, 
    1790, 230, 413, 681, 393, 1461, 60, 370, 
    1752, 1744, 934, 1010, 197
  ) 
  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 0.00159

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": 36,
      "filtered": 7.346936703,
      "index_condition": "cscart_product_prices.product_id in (74,1161,75,374,800,1136,224,795,1839,797,798,1409,367,1393,484,445,157,388,585,241,629,590,860,1790,230,413,681,393,1461,60,370,1752,1744,934,1010,197)",
      "attached_condition": "cscart_product_prices.lower_limit = 1 and cscart_product_prices.usergroup_id in (0,1)"
    }
  }
}

Result

product_id price
60 28000.00000000
74 44000.00000000
75 44000.00000000
157 46000.00000000
197 42000.00000000
224 22000.00000000
230 27000.00000000
241 0.00000000
367 43000.00000000
370 12000.00000000
374 37000.00000000
388 24000.00000000
393 31000.00000000
413 23500.00000000
445 32000.00000000
484 24000.00000000
585 26000.00000000
590 22000.00000000
629 46000.00000000
681 35000.00000000
795 22000.00000000
797 11000.00000000
798 22000.00000000
800 23500.00000000
860 42000.00000000
934 0.00000000
1010 60000.00000000
1136 23500.00000000
1161 44000.00000000
1393 38000.00000000
1409 46000.00000000
1461 22000.00000000
1744 0.00000000
1752 34000.00000000
1790 32000.00000000
1839 22000.00000000