Add the olive oil, lime juice, lime zest, cilantro, garlic, cumin, paprika, chili flakes, salt, and pepper to a large mixing bowl. Whisk to combine.
Add the chicken thighs and toss to coat evenly in the marinade. Cover and refrigerate for at least 30 minutes, up to overnight.
When ready to cook, heat a large skillet or grill pan over medium-high heat.
Add the marinated chicken thighs to the hot pan and cook for 6-7 minutes per side or until fully cooked through and nicely charred.
Remove from heat and let rest for 5 minutes before serving. Garnish with additional cilantro and lime wedges if desired.