Arriving T1 one almost literally passes thru duty-free on the way to baggage claim and aduana (customs). it has been quite a long time since I have arrived in T2 but the last time I remember being disappointed there was no duty-free before passing through aduana on arrival and I suspect that has not changed. If it has not changed you should still be able to purchase in the duty-free store in the terminal after clearing customs while waiting for your connection although it will not be tax free.
But if you dont have checked baggage how are you expecting to carry bottles in the cabin on the connecting flight? I am not sure Mexican security will allow that in the same way TSA sometimes does in the special sealed bags. Also, in my recent experience in Mexico, alcohol at my destination was significantly less expensive than in the airport (where for years it was the other way around - hence my disappointment about lack of duty free on arrival in T2).