Preheat the air fryer to 400°F (200°C) for 5 minutes.
In a shallow bowl, combine the flour, garlic powder, onion powder, smoked paprika, salt, and black pepper.
In a second shallow bowl, whisk together the eggs and water until smooth.
Place the panko breadcrumbs in a third shallow bowl.
Pat the chicken thighs dry with paper towels.
Dredge each chicken thigh first in the seasoned flour, shaking off excess.
Dip the floured chicken thigh into the egg mixture, coating completely.
Press the chicken thigh into the panko breadcrumbs, ensuring an even coating. Repeat for all thighs.
Lightly spray both sides of the breaded chicken thighs with cooking spray.
Place the chicken thighs in a single layer in the air fryer basket, skin side down. Do not overcrowd; cook in batches if necessary.
Air fry at 400°F (200°C) for 10 minutes.
Flip the chicken thighs over and air fry for an additional 10 minutes, or until the internal temperature reaches 165°F (74°C) and the coating is golden and crispy.
Remove the chicken thighs from the air fryer and let rest for 5 minutes before serving.