Body Temperature and Intelligence
It is entirely feasible that the pressures to have intelligent, tool using, social creatures can happen with cold blooded as well as warm blooded. It just hasn't really happened on earth (to my knowledge).
We are world building SE, though, so I am going to take my shot at making this plausible. IMHO, we just don't know enough about the genesis of our own species to know all the ramifications of fiddling with biology and ecology to know for sure how things will change.
A Plausible Path: Tree-Dwelling Lizards
Tree dwelling, generalist lizards could have taken similar paths as those bipedal mammals did. This includes thumbs for grasping, social behavior, tool use, moving out of trees... All those steps to get from a rat to a human could potentially have happened for a lizard to lizard-man with some changes.
A big change I recommend is raising the temperature of their world. This makes their cold bloodedness a benefit. Hypothermia still happens, just not as easily or often as it would here, and plenty of environments are still deadly without fire and tool use.
Additionally, there may be greater emphasis on trapping than active hunting. Endurance hunting may not be their cup of tea, as they will likely not evolve sweat. Trap making is much more lazy way of getting a meal, and ambush hunting may work for them, too!