the easiest method i can think of would be to have when the breaker is activated it changes a variable on the door, that variable would be connected to a branch and would prevent the script from running until the variable becomes set to true.
the below picture shows what i mean. near the bottom you will see the blueprint for the breaker where the breaker is activated using the 3 key, then it takes a reference to the door and sets its unlocked variable to true. to get this reference you would just need to make a variable of type actor then it public and set it from the details panel once you put the blueprint in your scene. as for the door blueprint near the top, its a basic on overlap activation but it runs through two checks before actually running the script to open the door. the first check is to see if its the player that is overlapping, and the second checks to see if the door is unlocked. if either check is false then the door will not open.
