There are much worse things people do to pet snakes than smoke near them. But that said, I would think it both possible and wise to avoid smoking in the room where the snake lives. Even compared to a dog, cat, or human family member, a snake can't so much as leave the room to avoid the smoke.
Not to mention that snakes have a sensitive sense of smell, and are much more olfactorily-oriented than we are (actually, that could be said about many of the animals we keep as pets). Maybe the constant smell of smoke doesn't overwhelm their sensory experience and maybe it does, but they can't tell us.

The actual effects of smoking vary; there are chain smokers who make it to 90 without getting lung cancer. But if you can keep the snake in a smoke free room it can't hurt.