Heat your air fryer to 400ºF.
In a bowl, combine the shrimp, olive oil, garlic, salt, lemon zest, and red pepper flakes (if using). Toss to coat.
Transfer the shrimp to the basket of your fryer. Cook for 5-8 minutes, shaking the basket halfway through, or until the shrimp are cooked through.
Pour the shrimp into a serving bowl and toss with lemon juice and parsley. Season with additional salt to taste.