Crush graham crackers into fine crumbs and melt the butter. Combine the crumbs with the butter and press into a pie dish. Chill for 15 minutes.

In a mixing bowl, combine fresh lemon juice, condensed milk, and lemon zest, then blend until smooth.

Gently fold in the whipped topping into the lemon mixture until smooth and no streaks remain.

Pour the filling into the chilled crust and spread evenly. Freeze for at least 4 hours or overnight.

Before serving, let the pie sit at room temperature for 10 minutes to soften slightly.