I have a baby corn snake which went missing from a locked cage?

It has been missing from 3-4 days and I dont know what to do ? Its kept in the cage and always under lock...How can it escape from there.......My husband wanted to get it out to feed it thats when we realised its missing...... I need to find it, have looked everywhere in the house....Can anyone give me sonme advice please...I hope it is still in the house and alive...