In a large bowl, combine the greek yogurt, minced garlic, olive oil, cumin, smoked paprika, turmeric, coriander, cayenne pepper, salt, black pepper, and lemon juice. Whisk together until the marinade is smooth and all the spices are evenly distributed.
Add the chicken thighs to the bowl and coat each piece thoroughly with the yogurt marinade, making sure every surface is covered. Cover the bowl with plastic wrap and refrigerate for at least 2 hours, or ideally overnight for maximum tenderness and flavor.
Remove the chicken from the refrigerator about 20 minutes before cooking to take the chill off. Shake off any excess marinade from each piece, leaving just a thin coating on the chicken. This ensures better browning in the air fryer.
Preheat the air fryer to 380 degrees F. Arrange the chicken thighs in the basket in a single layer, making sure the pieces do not overlap.
Air fry for 18 to 22 minutes, flipping the chicken halfway through, until the exterior is golden with lightly charred spots and the internal temperature reaches 165 degrees F. The yogurt coating should look beautifully caramelized.
Let the chicken rest for 5 minutes before serving. Garnish with fresh cilantro and serve alongside rice, warm flatbread, or a crisp salad.