Pre-heat your air fryer to 390°F. Spray the interior basket lightly with the cooking oil.
In a medium bowl, whisk together the flour, seasoning salt, and Old Bay seasoning.
Dredge a chicken thigh through the flour mixture until well coated. Shake off any excess, then dredge the chicken thigh in the egg mixture, coating completely. Return the chicken thigh to the flour mixture and dredge it again until completely coated. Shake off any large excess of flour.
Place the chicken thigh on a plate, then repeat the process with the other three thighs.
Once done, spray the tops of the chicken thighs with cooking oil until they are evenly coated to prevent any dry spots of flour.
Place the chicken thighs in the basket, skin side down (top side down), leaving enough room between them for air to circulate. Spray the bottom of the chicken thighs with the cooking spray.
Cook the chicken for 15 minutes, then open it and with a pair of tongs. Turn each piece of chicken over. If desired, you can spray the top again with cooking oil for extra crispness. Continue cooking the thighs for another 8-10 minutes or until the chicken is 185°F when tested with a meat thermometer.
Remove to a platter and serve hot.
Notes
Calorie information includes all of the flour and egg mixture, so actual calories will be slightly less than shown, as you don't use it all.