SELECT 
  cscart_ult_product_prices.product_id, 
  MIN(
    IF(
      cscart_ult_product_prices.percentage_discount = 0, 
      cscart_ult_product_prices.price, 
      cscart_ult_product_prices.price - (
        cscart_ult_product_prices.price * cscart_ult_product_prices.percentage_discount
      )/ 100
    )
  ) AS price 
FROM 
  cscart_ult_product_prices 
WHERE 
  cscart_ult_product_prices.product_id IN (
    10421, 10422, 10423, 10424, 10425, 10426, 
    10427, 10428, 10429, 10430, 10431, 
    10432, 10433, 10434, 10435, 10436, 
    10437, 10438, 10439, 10440, 10441, 
    10442, 10443, 10444, 10445, 10446, 
    10447, 10448, 10449, 10450, 10451, 
    10452, 10453, 10454, 10455, 10456, 
    10457, 10458, 10459, 10460, 10461, 
    10462, 10463, 10464, 10465, 10466, 
    10467, 10468
  ) 
  AND cscart_ult_product_prices.lower_limit = 1 
  AND cscart_ult_product_prices.company_id = 1 
  AND cscart_ult_product_prices.usergroup_id IN (0, 0, 1) 
GROUP BY 
  cscart_ult_product_prices.product_id

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}