Preheat the air fryer to 390°F (200°C).
In a small bowl, whisk together the olive oil, lemon juice, Dijon mustard, kosher salt, garlic powder, black pepper, and cayenne pepper until smooth.
Brush the seasoning mixture evenly over the tops of the frozen salmon fillets.
Arrange the fillets in a single layer inside the air fryer basket, leaving space between each piece for proper air circulation.
Cook the Frozen Salmon in the Air Fryer for 12–18 minutes, depending on the thickness of the fillets.
Check that the thickest part reaches an internal temperature of 145°F (63°C).
Remove carefully and serve immediately with fresh lemon wedges.