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 (
    73214, 73213, 73212, 73211, 73210, 73209, 
    73208, 73207, 73206, 73205, 73204, 
    73203, 73202, 73201, 73200, 73199, 
    73198, 73197, 73196, 73195, 73623, 
    73622, 73621, 73620, 73619, 73618, 
    73617, 73616, 73615, 73614, 73613, 
    73612, 73509, 73285, 73241, 73408, 
    73402, 73401, 73337, 73336
  ) 
  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 0.00059

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_ult_product_prices range usergroup,product_id,company_id,lower_limit,usergroup_id usergroup 13 1 Using where