In a medium bowl, stir together graham cracker crumbs, sugar and melted butter until well combined. Press mixture into a 9-inch pie plate. Bake at 375° F for 7 minutes. Cool completely.
In a medium bowl, combine condensed milk, sour cream, lime juice and zest. Mix well and pour into baked graham cracker crust. Tap pie plate gently on the counter to release any air bubbles.
*Nutritional information is an estimate. Please consult a doctor or nutritionist for the most accurate nutritional info.