In a large bowl, combine the Greek yogurt, lemon juice, minced garlic, grated ginger, ground cumin, ground coriander, smoked paprika, ground turmeric, cayenne pepper, kosher salt, and black pepper. Mix well to form the marinade.
Add the chicken thighs to the bowl and coat each piece thoroughly with the yogurt marinade. Cover the bowl with plastic wrap and refrigerate for at least 1 hour, preferably 4 hours or overnight for best flavor.
Preheat the air fryer to 380°F (193°C) for 5 minutes.
Remove the chicken thighs from the marinade, allowing excess marinade to drip off. Place the chicken thighs skin-side down in the air fryer basket in a single layer without overcrowding. You may need to cook in batches.
Cook the chicken thighs at 380°F (193°C) for 10 minutes. Then flip the chicken thighs skin-side up and cook for an additional 8-10 minutes, or until the internal temperature reaches 165°F (74°C) and the skin is crispy.
Remove the chicken thighs from the air fryer and let them rest for 5 minutes before serving.