Not the greatest idea, but it really depends on the size of the room and if you keep the rats and their enclosures immaculately clean and odor free at all times so you are not constantly teasing your snakes with the scent of rodent always in the air close to them.
I have 4 breeding quads of ASF's in the same room with 13 snakes. They all eat just fine. When i go to handle the smaller snakes they will be a bit nippy till i pick them up.
I have a VERY small animal room and breed rats, ASF's, and button quail. All of my reptiles (mostly snakes) are in the same room and I have no issues at all.