I had about the same layover. I had a friend who works in DF pick me up. I was coming in Aero Mar and leaving on Mexicana. He picked me up at the AM business terminal so there was no terminal traffic to deal with. Basically had enought time to go eat lunch. I almost missed the plane coming back because of traffic. My friend drove like a mad man to get me back on time, even going down one way streets the wrong way.

I got to the airport with about 35 minutes until flight departure. I went to the Mexicana FC counter and tipped $20US. She allowed me to check in and escorted me through security and to the gate. Made it with no time to spare.

Moral of the story, I had 7 hours, and that was barely enought time. Mexican lunches take a long time and DF traffic at 4pm can be very bad.

The terminal is interesting enough to explore, especially if you can get into airline lounges.

The airport is not really by anything worth seeing, and is not the best part of town to wander around in. Safe bete is to stay in the terminal.