SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '529412cb672173da030c0c56a2c4fc708fc5e990a2e39b9c25bb0a843f5e489e' 
  AND token = 'nq51IoeB8iBDINdx4ZAp7DzmjYZiXAjGYcqJfxJU484=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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