SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bfa152631886c8bdb20bc0946f7934adeaff82bc751f89bfed6d8a37a68639f' 
  AND token = 'vcN6FdOiv6J9DbvwfO4ZkXqqBIpEfAyofNRGDXHjvcA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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