breakfast at fonda margarita before a 1020 am international flight?

Hello everyone, I want to ask you if my plan is reasonable as me and my wife want to check out this beloved Fonda prior to our flight back home. We live in NY and our flight out of MEX is at 1020AM. From what I've gathered, Fonda opens at 630AM. There should not be much of a line at that point. I cannot find how long it generally takes to dine there. But possibly 30 minutes? It takes about 25 minutes from there to the airport so best case scenario I get to the airport between 730-8am according to my calculations. Please let me know if I am missing something obvious or do you know if I am able to dine in earlier than 630?

This is address of restaurant. Adolfo Prieto 1364 B, Tlacoquemecatl del Valle, Benito Juárez, 03100 Ciudad de México, CDMX, Mexico

And we are not checking bags