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 (
    105207, 105206, 105205, 105204, 105203, 
    105202, 105201, 105200, 105199, 105198, 
    105197
  ) 
  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 0.00053

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_product_prices range usergroup,product_id,lower_limit,usergroup_id usergroup 9 22 Using where

Result

product_id price
105197 1.69000000
105198 1.69000000
105199 1.69000000
105200 1.69000000
105201 1.69000000
105202 1.69000000
105203 1.69000000
105204 1.69000000
105205 1.69000000
105206 1.69000000
105207 1.69000000