>> When I search the Word of G-d for “Keys” I only find two citations <<
That’s why proof-texting is a bad idea. “Keys of the kingdom” is the actual expression, and it refers to the authority yielded by an absent king to his vicar, who was called a “regent.” A vicar acts under the authority of another authority, not as his replacement, but does have full authority. Because of this passage, the Pope is referred to as “Vicar of Christ.”
Mind you, Jesus says Peter WILL receive the keys. He was not given them until after the Resurrection (Jesus says, “I am the good shepherd,” but tells Peter, “herd my lambs”.), for Jesus knew that Peter would deny Him three times.
And the early church fathers did NOT, interpret any sole, exclusive receiving of the "keys" in the single person of Peter at all, nor any petrine primacy in the bishops of Rome, as Rome later came to assert, causing schism within the Church.