Does luck elixar help with loot from Locked box?

I'm wondering if I buy luck elixar would it help me get better loot out of locked boxes

No. Loot Elixirs will only have an effect with the initial drop from a boss or mob in the game. It will increase your chances of getting locked boxes, and locked crates as well as legendaries, but items inside of a chest or crate are not affected by luck elixirs or the luck amulet

Thank you :)