SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4556033baff8d8e956284366ddd8ef794ae608a4fa71c99c0a47ce9658b91115' 
  AND token = 'lZ+7d2DPsh+E6OjlqQ/NOgnKIlWxeH31Hxc/IhLdGQA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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