Preheat the oven to 350 degrees F. Mix the graham cracker crumbs, sugar, melted vegan butter, and salt until evenly moistened.
Press the crust firmly across the bottom and sides of a 9-inch pie dish. Bake for 9 minutes, then cool for 10 minutes.
Whisk the condensed coconut milk, coconut cream, key lime juice, cornstarch, key lime zest, vanilla, and salt in a saucepan until smooth.
Cook the filling over medium heat for 5 to 7 minutes, whisking constantly, until it thickens and begins to bubble.
Pour the hot filling into the crust and smooth the surface. Cool at room temperature for 30 minutes.
Refrigerate the pie for at least 6 hours, or overnight, until completely chilled and firm.
Top with dairy-free whipped topping and key lime zest shortly before serving.
