SQL 'like' faster than '=' performance using inner join

Question

We have 2 tables:

CREATE TABLE `task_information` 
(
    `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
    `project_id` varchar(64) NOT NULL DEFAULT '0',
    `task_id` varchar(64) NOT NULL DEFAULT '0',
    `machine_id` varchar(16) NOT NULL DEFAULT '0',
    PRIMARY KEY (`id`),
    KEY `idx_project` (`project_id`,`task_id`),
    KEY `idx_task` (`task_id`)
) ENGINE=InnoDB AUTO_INCREMENT=1100523 DEFAULT CHARSET=utf8mb4

CREATE TABLE `task_process` 
(
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `task_id` varchar(64) NOT NULL DEFAULT '0',
  `project_id` varchar(64) NOT NULL DEFAULT '0',
  `status` varchar(16) NOT NULL DEFAULT '0'
  PRIMARY KEY (`id`),
  UNIQUE KEY `uniq_task` (`task_id`)
) ENGINE=InnoDB AUTO_INCREMENT=1096437 DEFAULT CHARSET=utf8mb4

These two tables have a one-to-one relationship based on "task_id".

The two tables have almost 800K entries. Also there will be lots of "success" in the "status" column. The "status" column has exactly three values: "success", "fail" and "start", their ratio is roughly 100:1:1.

And now I want to select the task_id where machined_id is specified and the status equals "success", my sql query looks like this:

select * 
from task_information 
inner join task_process on task_process.task_id = task_information.task_id  
                        and task_information.machine_id = "RA00906" 
where task_process.status="success"\G;

This one takes 4.96s, the result from explain is as follows:

*************************** 1. row ***************************
id: 1
select_type: SIMPLE
    table: task_process
partitions: NULL
     type: ALL
possible_keys: uniq_task
      key: NULL
  key_len: NULL
      ref: NULL
     rows: 760145
 filtered: 10.00
    Extra: Using where
*************************** 2. row ***************************
       id: 1
select_type: SIMPLE
    table: task_information
partitions: NULL
     type: ref
possible_keys: idx_task
      key: idx_task
  key_len: 258
      ref: task_process.task_id
     rows: 1
 filtered: 10.00
    Extra: Using where

But if I change "=" to "like" the speed becomes much faster (around 0.9 seconds):

select status 
from task_information 
inner join task_process on task_process.task_id = task_information.task_id 
                        and task_information.machine_id = "RA00906" 
where task_process.status like "success"

The result from explain is like this:

*************************** 1. row ***************************
           id: 1
  select_type: SIMPLE
        table: task_information
   partitions: NULL
         type: ALL
possible_keys: idx_task
          key: NULL
      key_len: NULL
          ref: NULL
         rows: 759749
     filtered: 10.00
        Extra: Using where
*************************** 2. row ***************************
           id: 1
  select_type: SIMPLE
        table: task_process
   partitions: NULL
         type: eq_ref
possible_keys: uniq_task
          key: uniq_task
      key_len: 258
          ref: task_information.task_id
         rows: 1
     filtered: 11.11
        Extra: Using where

Both of these queries return around 500 rows, but "LIKE" is much faster than "=" even though functionally they should be roughly the same.

Can someone please explain to me the reason behind this?

tl;dr using "LIKE" is much faster than "=" in the same "inner join" query, what is the reason behind this?