I am guessing your in a glass tank. If so go buy some plexi, cut to size (should fit snug, or if your good make it so it can slide like you lid. There are many options here to make it work)
Now....about 10 (more or less as you see fit) holes in the lid (plexi) and there you have it. enough air for the snake and keeping the tank all closed off like that keeps humidity up with little effort like a tub and it still pretty! Drill more holes to keep humidity down as needed.
Worked for my gf's crested like a CHARM. Also a bigger water bowl will DEF help with this process.
This will cost you no more than 15 bucks at a home depot or lowes