Place the room temperature cream cheese in a large mixing bowl.
Beat with an electric mixer until smooth and creamy.
Add the sweetened condensed milk and mix until fully combined.
Add the vanilla extract, salt, and lemon zest.
Mix until smooth.
Slowly add the fresh lemon juice and beat until the filling is creamy and fully combined.
Scrape down the sides of the bowl with a rubber spatula.
Pour the lemon filling into the graham cracker crust.
Smooth the top.
Cover and refrigerate for at least 4 hours, or overnight for the firmest slices.
Top with whipped cream before serving.
Garnish with extra lemon zest or lemon slices if desired.
Serve cold.