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 (
    6432, 6433, 6434, 6435, 6436, 6437, 6438, 
    6439, 6440, 6441, 6442, 6443, 6444, 
    6445, 6446, 6447, 6526, 6527, 6528, 
    6529, 6530, 6531, 6532, 6533, 6534, 
    6615, 6616, 6617, 6618, 6619, 6620, 
    6621, 6622, 2272, 2273, 2274, 2275, 
    2276, 2340, 2341, 2342, 2343, 2344, 
    2345, 2346, 2347, 2348, 2421
  ) 
  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"
  }
}