Rinse the chicken hearts under cold water and pat them very dry with paper towels. Trim away any excess fat or connective tissue, and cut any larger hearts in half so they are all roughly the same size for even cooking.
In a mixing bowl, toss the chicken hearts with olive oil, smoked paprika, garlic powder, onion powder, cumin, salt, black pepper, and cayenne pepper. Make sure every heart is well coated. Let them sit for 10 minutes to absorb the seasoning.
Preheat the air fryer to 400 degrees F for 3 minutes.
Spread the chicken hearts in a single layer in the air fryer basket. Avoid overcrowding so air can circulate properly. Cook for 10 to 12 minutes, shaking the basket at the halfway mark, until the hearts are deeply browned on the outside and cooked through but still juicy inside.
Transfer the chicken hearts to a serving plate and squeeze fresh lime juice over the top while they are still sizzling hot.
Garnish with chopped cilantro and serve immediately as an appetizer or snack. These pair wonderfully with a squeeze of extra lime and your favorite hot sauce.