In a bowl, mix together garlic, mustard, brown sugar, oil, and spices.
Rub the chicken drumsticks with marinade and refrigerate to marinate for about 20-30 minutes.
Grease the Air Fryer Basket with cooking spray and then slide inside.
Adjust the temperature of Air Fryer to 390 °F to preheat for 5 minutes.
After preheating, arrange the chicken drumsticks into the greased Air Fryer Basket in a single layer.
Slide the basket into Air Fryer and set the time for 10 minutes.
After 10 minutes of cooking, adjust the temperature to 300 °F for 10 minutes.
After cooking time is finished, remove the chicken drumsticks from Air Fryer and serve.