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 (
    6418, 6419, 6420, 6421, 2823, 2824, 2825, 
    2826, 6408, 6409, 6410, 6411, 6412, 
    2827, 2828, 2829, 2830, 2831, 6413, 
    6414, 6415, 6416, 2928, 2929, 2930, 
    2931, 2932, 6513, 6514, 6515, 6516, 
    3032, 6609, 3028, 3029, 3030, 3031, 
    6605, 6606, 6607, 6608, 6610, 6611, 
    6612, 6613, 3024, 3025, 3026
  ) 
  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 0.00032

JSON explain

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