Nope... don't worry about "LT". The only other spec I've heard of with chains is "S" clearance. Those are usually cables, and it's more of a concern for cars to clear some suspension components. The owners manual will mention this if S clearance chains/cables are required. Toyota usually is pretty good about giving the exact specifics of what's required for chains/cables.
Most chains will fit a range of tire sizes. As an example chains for 215/60R16 or 225/55R16 will also fit 205/65R15, and the list for that particular size is more extensive than that.
Since you're getting used chains, visually inspect the links/cables, hooks on sides (that goes the circumference of the tire) and the rungs (the sections that run width wise over the tire threads). You want to make sure they're not worned out or fatigue to a point where it could break on you. The carnage from broken chains can get real ugly. A friend of mine had a rung break on him and it dinged, dented and scratched the heck out of the fender.