Pulse graham crackers, 2 teaspoons white sugar, and cinnamon in a food processor. Pour in melted butter; pulse until fine crumbs form. Pat the crust into the bottom and 1 inch up the sides of a 6-inch springform pan. Put the pan in the freezer for 20 minutes.
Mix cream cheese in the bowl of a stand mixer on medium-low speed until aerated and creamy, about 4 minutes. Add 2/3 cup sugar and salt; mix for 4 minutes more. Add vanilla extract and lemon zest; mix batter for 1 minute more.
Crack 1 egg into the batter; mix for 1 minute. Add remaining egg; mix for 1 minute more. Stir in the sour cream; mix until it has disappeared into the batter, about 1 minute. Pour into the crust-lined pan. Make a loose tent over the pan with aluminum foil.
Pour 1 1/2 cups of water into the bottom of the Instant Pot; add the trivet. Lower the filled springform pan carefully into the Instant Pot®. Lock the lid into place.
Choose the "Manual" setting; select high pressure. Set cook time for 40 minutes. When the timer goes off, allow pressure to naturally release for 18 minutes. Remove the lid. Check for doneness; edges should be set and the center should jiggle slightly when shaken.
Transfer the cheesecake to the refrigerator. Chill for at least 2 hours, preferably overnight.