looks rat snake-ish to me, but i'm a python guy....
btw, the anal scale (or plate) is exactly what it sounds like
look down by the cloaca (where it poops). the scale that covers the cloaca (place where all the action takes place) is the anal scale/plate. it will either be a single scale or divided.
if you'd rather not get "that personal".....rat snakes have keeled (somewhat lightly though) covering their body and king snakes have smooth scales covering their body....