MySQL 5.7 introduced INNODB_TEMP_TABLE_INFO table added into INFORMATION_SCHEMA.

Using INNODB_TEMP_TABLE_INFO, you can get A list of all active Temp Table of MySQL InnoDB Instance.
You can get the information of all active user created and system created Temp Tables.

The Database Administrator can use this script for monitoring total Temp Table in MySQL Server.
Unnecessarily, we should not create a TEMP Table because It requires temporary disk + memory storage and degrade the overall performance of MySQL Server.

Once you get the list of tables using INNODB_TEMP_TABLE_INFO, you can get system generated Temp Table Name.

Check existance of INNODB_TEMP_TABLE_INFO:

SHOW TABLES FROM INFORMATION_SCHEMA LIKE 'INNODB_TEMP%';

Create two sample Temporary Table:

CREATE TEMPORARY TABLE ABC (ID INT, Name VARCHAR(50));
CREATE TEMPORARY TABLE XYZ (ID INT, Name VARCHAR(50));

Get the information of Temp Table:

SELECT * FROM INFORMATION_SCHEMA.INNODB_TEMP_TABLE_INFO

*************************** 1. row ***************************
            TABLE_ID: 93
                NAME: #sqlcec_9_bec
              N_COLS: 5
               SPACE: 76
PER_TABLE_TABLESPACE: FALSE
       IS_COMPRESSED: FALSE
*************************** 2. row ***************************
            TABLE_ID: 92
                NAME: #sqlcec_9_beb
              N_COLS: 5
               SPACE: 76
PER_TABLE_TABLESPACE: FALSE
       IS_COMPRESSED: FALSE
2 rows in set (0.01 sec)

I already shared a article on HEAP Table. I discussed Memory Storage Engine of MySQL.

After discussing this topic, there is a confusion.

What is the difference between Temporary Table and Memory Table?

The main difference is, Temporary Table is only for running current session.
Once the session completed its execution, Temporary Table will discard from memory.
You cannot use Temporary Table for multiple sessions.
As we previously discussed, that Memory Table can hold data for across all running sessions and connections.

Temporary Table stores all data and table definition in an interim disk file.

Memory Table stores all data into Memory and stores table definition into .frm disk file.

Temporary Table can also store all data into memory, but for that, you have to create a Temporary Table using Memory Engine.