SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e7b712b3323582288827c96ce9f4db0fb5a8de367d5aaa2061c1a643f287e1f' 
  AND token = 'E5yu4qiIYYLh9JN8g7RrnOMp3vfy/BtkaVGwD83gHhA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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