Is it.
Based on the GDS response:
Minimum Connecting time Int flight to Int flight is 75 minutes.
I am not even sure they will be willing/able to check your baggage through with such the tight connection.
Also US-bound flights have a lot of gate formalities - passport/visa/ESTA check, first night address collection (unless US citizen), manual search for SSSS (Subject to Secondary Security Search). IMHO 40 minutes might be not enough to connect to a US-bound flight.
Yesterday, TK sold me a 55 minute connection EWR IST MLA. Is MCT really 75 minutes at IST?