Command-line keychain access not showing any results
I have not scored enough points (yet) to mark this as a duplicate, but on  How can I access the keychain remotely from the command line? you will find the solution to help you out here.

In short: Add "security" to the "Access Control", re-login and run security unlock-keychain ~/Library/Keychains/login.keychain before running security find-generic-password.