I've found in my experiences, that cats weren't too interested in killing snakes. The ones my cats brought me when I was on the farm, were in good shape except for minor puncture wounds that healed after a few days of treatment.

One baby snake that escaped last fall, was found a week later when I heard one of the cats making a "trilling" call that cats make to call their kittens or call another cat to come see something they've found.
I went into the living room and saw a circle of cats sitting and watching something in the center of their circle. That something turned out to be the escaped baby snake, unharmed, and the cats were just watching it and one sometimes would reach out to try to touch it and the snake would move and the cat would yank its paw back right away.

When I've been handling the snakes outside their cages, the cats would keep their distance, clearly wary of this weird creature that doesn't have legs and whose head and tail look much alike (in the cat's point of view).

When I had my smaller rescue garter escape, the cats had plenty of chances to have caught it before the snake found me. The snake found me when I went over near my dresser, which has shelves and a variety of objects on those shelves. When I came close to the dresser, the snake came out of a vase of artificial roses and started trying to come over to get onto my shoulder from the vase! I was so relieved and happy that my fugitive snake decided to find ME!
And as long as I see no evidence of death of the fugitives that haven't been found yet, I keep leaving pcv and bottle traps, water dishes, etc, around for them in hope that they will turn up one day alive and ready to go home where food is served to them by their willing human servant while the snakes enjoy their cushy lives in captivity!