Mexican restaurants keep chips warm by using nacho chip and Tortilla chip warmers.
The nacho chip warmer works to warm the tortilla chips and nacho chips warm after heating them up.
Mexican restaurants get their chips so thin by using restaurant grade thin corn tortillas, then they cut them and deep fry them.
The ones you buy at the store are too thick for this - you could try contacting a food supply company and see if they can tell you where to buy.
Any half decent Mexican restaurant cooks their own chips, and ideally they hit the table still warm and fresh.
All of the places I frequent locally have distinctly unique chips.
To reheat chips place your chips in a microwave-safe bowl.
Cover the dish with a damp paper towel to help retain moisture.
Microwave the chips in bursts of 30 seconds to ensure they don't overcook and become too soft.
Remove the dish from the microwave and let the chips cool for a few minutes before serving.