Place the chicken breast between two pieces of parchment paper and pound to an even half-inch thickness for uniform cooking.
In a shallow bowl, whisk the egg white until slightly frothy; in a second bowl, combine almond flour, smoked paprika, garlic powder, salt, and pepper.
Dip the chicken breast into the egg white, letting the excess drip off, then press firmly into the almond flour mixture to coat both sides.
Lightly coat the air fryer basket with avocado oil spray and cook the chicken at 375°F for 12-15 minutes, flipping halfway, until golden and cooked through.
While the chicken cooks, whisk together the honey and Dijon mustard in a small bowl until the glaze is smooth and well-combined.
Toast the whole wheat bun until lightly browned, then layer with the crispy chicken, a generous drizzle of honey-mustard, lettuce, and tomato.