Prepare the crust by combining gluten-free graham cracker crumbs and granulated sugar in a bowl. Add melted butter and mix until it resembles wet sand. Press into a 9-inch pie pan and bake at 350°F for 8-10 minutes. Let cool.

In a separate bowl, whisk egg yolks until smooth. Add sweetened condensed milk, fresh key lime juice, and lime zest. Whisk until smooth.

Pour the filling into the cooled crust and spread evenly. Bake for 10-12 minutes until set but slightly jiggly in the center. Let cool to room temperature.

Refrigerate the pie for at least 2 hours to allow flavors to meld and filling to set.