How to overcome error #1032 - Unable to find entry?

Question

MySQL

Fires on a request:

DROP TABLE IF EXISTS `mdf_prefix_info`;
/*!40101 SET @saved_cs_client     = @@character_set_client */;
/*!40101 SET character_set_client = utf8 */;
CREATE TABLE `mdf_prefix_info` (
  `site_url` varchar(249) NOT NULL,
  `site_prefix` varchar(64) NOT NULL,
  `site_theme` varchar(255) NOT NULL,
  `site_isdev` int(11) NOT NULL,
  `site_lang` varchar(64) NOT NULL,
  `site_lang_name` varchar(255) NOT NULL,
  `site_enabled` int(11) NOT NULL,
  `api_key` varchar(255) NOT NULL,
  `api_master` int(1) NOT NULL,
  UNIQUE KEY `site_url` (`site_url`) USING HASH
) ENGINE=MyISAM DEFAULT CHARSET=utf8mb4;
/*!40101 SET character_set_client = @saved_cs_client */;

--
-- Dumping data for table `mdf_prefix_info`
--

LOCK TABLES `mdf_prefix_info` WRITE;
/*!40000 ALTER TABLE `mdf_prefix_info` DISABLE KEYS */;
INSERT INTO `mdf_prefix_info` VALUES ('lhtest.webtm.ru','gpro_','',0,'en-gb','English',1,'',0);
/*!40000 ALTER TABLE `mdf_prefix_info` ENABLE KEYS */;
UNLOCK TABLES;

Answer 1

Well you blocked record in the table!
LOCK TABLES `mdf_prefix_info` WRITE;
Naturally INSERT does not work!

Answer 2

There are no complaints about the code itself, it works without problems.
DEMO
Hike, it's phpmyadmin once again showed his pig's snout...