In a mixing bowl, whisk together the lemongrass powder, olive oil, soy sauce, lime juice, Worcestershire sauce, garlic salt, and lemon pepper seasoning until well combined.
Add the chicken thighs to the bowl with the marinade, ensuring each piece is thoroughly coated. Cover and marinate in the refrigerator for at least 30 minutes or overnight.
Preheat your air fryer to 400°F (200°C).
Place the marinated chicken thighs in the air fryer basket, skin side down, and cook for 12 minutes. Flip the thighs and cook for an additional 12-15 minutes until the internal temperature reaches 165°F (75°C).
Remove the chicken from the air fryer, let it rest for a few minutes, garnish with scallions if desired, and serve hot.