Sorry to hear your snake is MIA. Try this:
Get a metal wire 'cage' and place a live rat inside. Any hungry snake will be attracted to the racket (rats are noisy and nosy creatures). My burm likes to hide up high, and currently has made his 'home' at the very tip-top storage shelf in his closet. (The walk-in is modified to be an enclosure for him). You would be surprised where they can go and don't give up hope... if your apartment is rat/mouse free he'll come out some night looking for food. Be patient and be thorough. Good luck, and keep us updated!