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 (
    68280, 68279, 68278, 68277, 68276, 68275, 
    68274, 68575, 68204, 68406, 68375, 
    78288, 78287, 78286, 78285, 78284, 
    78283, 78282, 78281, 78280, 78279, 
    78278, 78277, 78276, 78275, 78274, 
    78273, 78272, 78271, 78270, 78269, 
    78268, 78267, 78266, 78265, 78264, 
    78263, 78262, 68395, 68189
  ) 
  AND cscart_product_prices.lower_limit = 1 
  AND cscart_product_prices.usergroup_id IN (0, 1) 
GROUP BY 
  cscart_product_prices.product_id