Preheat the air fryer to 400°F for 3 minutes.
Pat chicken thighs completely dry with paper towels.
Lightly brush thighs with olive oil or use a light spray to coat.
In a mixing bowl, combine salt, black pepper, garlic powder, onion powder, paprika, dry mustard, and cayenne.
Coat each thigh evenly with the dry rub, pressing to adhere.
Place thighs in a single layer in the air fryer basket without touching.
Cook at 400°F for 18 minutes without opening the basket.
Check that the internal temperature reaches 165°F using an instant-read thermometer.
Let rest for 5 minutes before slicing or serving.