In a medium bowl, combine the panko breadcrumbs, garlic, smoked paprika, salt, black pepper, and cayenne pepper (if using). In another bowl, place the all-purpose flour. In a third bowl, beat the eggs.
Dip each shrimp in the flour, shaking off any excess, then coat it in the beaten eggs, and finally dredge it in the panko mixture, pressing lightly to ensure it sticks well. Set aside on a plate.
Preheat your air fryer to 400°F (200°C) for about 5 minutes.
Lightly spray the air fryer basket with cooking spray or olive oil. Arrange the coated shrimp in a single layer, making sure they are not overcrowded. You may need to do this in batches. Spray the tops of the shrimp lightly with cooking spray or drizzle with olive oil. Cook for 8-10 minutes, flipping halfway through, until golden and crispy.
While the shrimp are cooking, whisk together the mayonnaise, minced garlic, lemon zest, lemon juice, Dijon mustard, salt, and pepper in a small bowl until smooth and well combined. Adjust the seasoning to your taste.
Once the shrimp are done, remove them from the air fryer and garnish with chopped fresh parsley. Serve immediately with the lemon aioli on the side for dipping.