To do so in a change node you can use transform syntax and a ternary statement.
e.g
[{"id":"47918bd2289f985c","type":"inject","z":"452103ea51141731","name":"","props":[{"p":"payload"},{"p":"topic","vt":"str"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"[{\"one\":1,\"two\":2},{\"one\":2,\"two\":2}]","payloadType":"json","x":110,"y":3920,"wires":[["cdc9af5490fc52a1"]]},{"id":"cdc9af5490fc52a1","type":"change","z":"452103ea51141731","name":"","rules":[{"t":"set","p":"payload","pt":"msg","to":"$$.payload ~> |$|{\"one\": $.one = 1 ? 3 : $.one}|","tot":"jsonata"}],"action":"","property":"","from":"","to":"","reg":false,"x":260,"y":3920,"wires":[["56bf43241f9cde0b"]]},{"id":"56bf43241f9cde0b","type":"debug","z":"452103ea51141731","name":"debug 109","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":450,"y":3920,"wires":[]}]
Expression for the example object, you will need to edit for your array object as you failed to provide an example.
$$.payload ~> |$|{"one": ($.one = 1 ? 3 : $.one)}|
Any property named one with value 1 will be set to 3.