SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cbf42a24b93f5d82ed2a71f04d0ed673b1a4110d798b9a69fe14c6e8340c770' 
  AND token = 'WOBvo0F9SORTG8KUra6412EMrZyiis0djguFPCJNXK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}