SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '543a70888ac64effc9d17458b81e79d0c0041d31d8ea453e895fe9b3bfe09ca6' 
  AND token = 'etrE85uClbNqgy3MlhkH3mFz9x9+X0LWKBZ+DFTB9BA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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