How to check if an IC is fried?
The chip is dead. 

As you said yourself, it got hot enough to burn your finger and also burn the epoxy case (hence smoke), both of which mean it has quite literally fried.



In general, the answer to the question "is there a way to check if an IC with unknown condition is 100% functional?" is simply maybe.  

The only way to test an IC is to try it, and if it behaves within the manufacturers specifications, then it is most likely functional - though it is not guaranteed to be.

The only way to be more sure (still not certain though) that you have a functional IC is to buy a new one. A new chip is much more likely to be functional than one of unknown condition.