Preheat an air fryer to 400 degrees F (200 degrees C).
Place 1 bread slice in the air fryer basket and cook in the preheated air fryer for 1 minute. Transfer to a plate. Repeat with remaining bread slice.
Remove casing from bologna, then use a knife to make 4 slits to prevent curling. Place in the air fryer basket and cook for 3 minutes. Flip bologna over and cook for 3 minutes more.
Spread mayonnaise onto 1 bread slice. Layer with cheese, bologna, tomato, and lettuce. Spread mustard onto remaining bread slice and top sandwich.