Pat the turkey breast completely dry with paper towels, removing all surface moisture.
Mix sea salt, smoked paprika, onion powder, garlic powder, and black pepper in a small bowl.
Gently loosen the skin and rub the seasoning mixture all over the turkey, including under the skin.
Refrigerate the turkey uncovered for 12 hours to dry brine.
Remove from the fridge 30 minutes before cooking. Brush half of the melted butter under the skin and the remaining butter over the surface.
Place the turkey breast side up on the roasting rack insert in the air fryer basket.
Air fry at 360°F for about 60 minutes (12 minutes per pound). Start checking internal temperature at 45 minutes.
Remove when internal temperature reaches 160°F in the thickest part of the breast (avoid the bone). The skin should be deep golden brown.
Let rest for 10 minutes; carryover cooking will bring it to 165°F. Carve along the breastbone and slice against the grain.