SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '259078a7d90edaf0aee6ee3b396e9643d55ce5e7ad1d124193cd057b30432bf9' 
  AND token = 'M7J60kXVvGZ9FaZEIbVdPWzf+TI0kKYYAsXHqht+vVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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