If the "clear water like fluid" and "sneezing" only happened that one time when you picked the snake up, and not since then, I think you may be good...
A URI would be getting worse, not better.
To be safe, keep the temps right on target, keep handling or any other stress to a minimum, but OBSERVE a few times the day. Any noises like hard breathing, whistling? Any yawning ? Sneezing? Discharge?
If anything at all seems "off", then yes, a vet visit is in order. The sooner, the better.
However...if that was just a "fluke" and the snake was drinking water just prior to being picked up, then a vet visit is needlessly stressful. Don't get me wrong, I'm all about taking them to the vet if need be. But I'm not a fan of taking reptiles "just in case" or for a general checkup (without reason).
The temps will be off and its stressful to the snake.
Keep a watchful eye (and ear) on the snake for a few days, and it goes without saying, make sure husbandry is spot on.