Ticks can get nasty if they're breeding. The only advantage in your case is, maybe only one tick got on your snake. My guys had the dreaded ticks in the past month; I am pretty sure my rescue-case bp was the culprit, although I had him quarantined in a seperate room, maybe a tick got on my shirt and travelled?
I was able to kill them off by frequently giving my snakes a warm dish soapy-water bath every 2 days. I treated the cages with Zoomed's anti mite/tick spray and it worked wonders.
what I would do in your case, is give my snake a bath, and see if I saw anything floating in the water afterwards. Just fill a few inches of water into a good-sized, securely-lidded rubbermaid (enough so that it covers your snakes back, but not so much water that he has to swim to stay aloft.) Keep him in there a few hours, and put a heatpad under the r-maid to keep the water warm. Afterwards, move the suds aside and see if you see any black dots in the water.