In a stand mixer fitted with the paddle (or with a handheld electric mixer) beat the condensed milk, egg yolks, lemon juice, and salt on medium for four minutes.
Pour the mixture into the baked pie crust. Bake until the center is set, about 10 minutes.
Cool on rack and then refrigerate until ready to serve, at least one hour.
Top with whipped cream, lemon slices, and lemon zest.
Notes
For a key lime pie, substitute fresh lime juice for the lemon juice.
Recipe by The Gingham Apron at https://www.theginghamapron.com/quick-and-easy-lemon-pie/