I've kept snakes in entirely enclosed boxes for short periods of time and they've been perfectly fine. I was evacuated due to a brush fire once and my snakes (ball pythons and kingsnakes at the time) all lived in sterlite tubs I hadn't had time to melt airholes in yet for over a week. I opened every cage every day to check the snakes and give them water, and they were all perfectly fine.
I wouldn't worry about not enough ventilation. Depending on species, the issue is too much ventilation. I set up kingnsakes (good starter snake) very successfully in naturalistic looking (glass with screen top) cages with rocks, corkbark stacks, and fake plants, but I've never wanted to try keeping a ground-dwelling species in a naturalistic setup with live plants, etc. A healthy adult snake will DEMOLISH your setup unless you've put lots of effort into keeping things sturdy and in place. And even then, they'll find a way to make a mess. Arboreal species are less destructive of cage setup, but they'll still cruise around and knock everything over if they feel like it.
Depending on where you are and what species you keep, the suitability of a screen top cage varies. I'm in southern california, inland a little ways, and it is dry as a bone all the time. The west coast kingsnakes, cornsnakes, milksnakes, rosy boas, etc, all do fine in a screen top cage with little or no tinkering. Anything from a more tropical climate, though, or even just things from the east coast, require something placed over the lid to keep moisture in.
I like vision cages for keeping snakes in, but they don't allow for much substrate depth if you have a species that likes to burrow. Glass tanks do allow you to fill them pretty full if you'd like to allow a burrowing species to root around to its heart's content.
There's pros and cons to every type of cage. 
~jen
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"We call them dumb animals, and so they are, for they cannot tell us how they feel, but they do not suffer less because they have no words."
- Anna Sewell (1820-1878)
