According to the Hadith, the Salaat of a man who consumes alcohol is not valid for 40 days.

Answer

The Hadith does not negate validity of his Salaat. Even if one had consumed alcohol, he is not absolved of performing Salaat. Salaat remains compulsory. As soon as he is sober, he has to perform his daily Salaat. The Hadith which mentions that the Salaat is not accepted for 40 days if one consumes liquor means that for 40 days one will be deprived of the reward and benefit of the Salaat. The Hadith does not mean that the obligation of Salaat is not or should not be discharged for 40 days. Salaat has to be compulsorily performed as soon as the person has sobered up.