I'd leave it alone...it's barely visible in photo, but I see some bent scales that suggest it's just a little scrape. Topical ointments won't do anything for unbroken skin, other
than make substrate stick to the scales. Don't bother. Might try to ascertain how it happened though...you aren't using any sort of cage decor like those skulls that snakes
can get stuck in the eye-sockets (as they grow), I hope? Or driftwood that has a similar restrictive opening that a snake might try to get thru?