Preheat the air fryer to 360°F (182°C).
Spread mayonnaise on one side of each slice of bread.
Layer the turkey, cheese, and mustard on the unspread side of one slice of bread.
Add lettuce and tomato slices on top of the cheese.
Top with the second slice of bread, mayo side facing in.
Place the sandwich in the air fryer basket.
Cook for 5-7 minutes, flipping halfway through.
Remove the sandwich and let it cool for a moment.
Slice in half and serve immediately.