The power to heal and prophesize and to destroy works of the devil are by the Holy Spirit. To imply that the Holy Spirit is “the keys” is not found in the Bible.
The keys represent authority in the Kingdom. The keys are found in the OT where they represented delegated authority from the King of Israel to one or more of his magistrates, generals, etc… The King possessed all legal power of the Kingdom; he could not carry out all his duties, so he had to delegate “the keys” to others who legally carried out his duties on his behalf. It’s like a court appointing a legal representative in a legal matter regarding a child or someone who is defunct.
We chip away at the devil’s plans every time we pray the “Prayer to St. Michael”.