这是我的桌子：

CREATE TABLE `cerp_oms_order` (
  `id` bigint NOT NULL,
  `company_id` bigint NOT NULL,
  `order_no` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `source_type` int NOT NULL,
  `shop_id` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `outer_shop` varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `origin_status` int NOT NULL,
  `system_status` int NOT NULL,
  `created_time` datetime DEFAULT NULL,
  `paid_time` datetime DEFAULT NULL,
  `sent_time` datetime DEFAULT NULL,
  `end_time` datetime DEFAULT NULL,
  `modify_time` datetime DEFAULT NULL,
  `delivery_deadline_time` datetime DEFAULT NULL,
  `amount` text CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL ,
  `spu_kind` int NOT NULL,
  `sku_kind` int NOT NULL,
  `total_quantity` decimal(16,4) NOT NULL,
  `buyer_id` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL,
  `outer_buyer_identifier` varchar(64) CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL DEFAULT '',
  `tax_info` varchar(256) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `warehouse_owner` int DEFAULT NULL,
  `warehouse_id` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `logistics_type` int NOT NULL,
  `logistics_outer_info` varchar(256) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `delivery_id` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `delivery_no` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `wave_no` varchar(64) DEFAULT '',
  `is_deleted` tinyint NOT NULL DEFAULT '0',
  `backend_processing_type` tinyint NOT NULL,
  `create_type` tinyint NOT NULL,
  `is_hang_up` tinyint NOT NULL,
  `hang_up_case_type` smallint DEFAULT NULL,
  `hang_up_case_id` bigint DEFAULT NULL,
  `rc_time` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `rm_time` datetime NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `vat` varchar(128) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `weight` decimal(16,4) NOT NULL DEFAULT '0.0000',
  `volume` decimal(16,4) NOT NULL DEFAULT '0.0000',
  `is_abnormal` tinyint NOT NULL DEFAULT '0',
  `estimate_profit` decimal(16,4) NOT NULL DEFAULT '0.0000',
  `business_man_id` varchar(256) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `business_man` varchar(256) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `currency` varchar(32) CHARACTER SET utf8 COLLATE utf8_general_ci DEFAULT NULL,
  `net_amount_summary` decimal(19,4) NOT NULL,
  `domestic_amount` decimal(19,4) NOT NULL,
  `secret_key` varchar(64) DEFAULT '',
  `secretKey` varchar(255) DEFAULT NULL,
  `sale_id` bigint DEFAULT NULL,
  `total_refund_include_tax` decimal(16,4) NOT NULL DEFAULT '0.0000',
  `total_refund_money` decimal(16,4) NOT NULL DEFAULT '0.0000',
  `total_refund_tax` decimal(16,4) NOT NULL DEFAULT '0.0000',
  `total_return_goods` decimal(16,2) NOT NULL DEFAULT '0.00',
  PRIMARY KEY (`id`),
  UNIQUE KEY `key_order_no` (`order_no`),
  KEY `idx_order_company_id` (`company_id`,`created_time`),
  KEY `IDX_RM_TIME` (`rm_time`),
  KEY `IDX_IS_ABNORMAL` (`is_abnormal`),
  KEY `cerp_oms_order_company_id_index` (`company_id`),
  KEY `idx_order_company_status_deleted` (`company_id`,`is_deleted`,`system_status`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_0900_ai_ci COMMENT='system order table'

explain select *
from cerp_oms_order
         inner join (select id
                     from cerp_oms_order
                     where source_type = 43
                     order by created_time) as tmp using (id);

使用内连接执行：7 ms，获取：109 ms

VS

explain
select *
from cerp_oms_order
where source_type = 43
order by created_time;

使用简单的where子句执行：80 ms，获取：138 ms

我不明白为什么使用内连接可以加快我的sql？