In a large bowl, mix together the graham cracker crumbs, shredded coconut, white sugar, and butter until well combined. Transfer the mixture into a 9-inch pie plate and press the crust along the bottom and up the sides of the pie plate. Bake in the preheated oven for 15 minutes then allow the crust to cool for 5 minutes before filling.
For the filling, whisk the condensed milk, coconut milk, Key Lime juice (or substitute), and egg yolks in a large bowl until smooth. Pour the filling into the prebaked pie shell, place the whole pie onto a rimmed baking sheet, and bake in the preheated oven for 40 minutes or until set and just slightly jiggly in the centre.
Remove the pie from the oven and allow it to cool to room temperature for 2 hours then transfer the pie to the fridge to chill completely for at least 3 hours.
When chilled, whip the cream, zest, coconut extract, and icing sugar with a whisk or electric mixer until stiff peaks form the dollop on top of the pie and finish with a sprinkling of toasted coconut.