How to update Timestamp Column where value is '0000-00-00 00:00:00' to '2020-01-01 11:28:47'

I am trying to update Timestamp field value to some expired date and want to set it
where values are '0000-00-00 00:00:00' But my query is not working. I have tried lot of solutions from stack overflow but none of them works

Here is my MySql Command

update users set `subscribe_at` = '2020-01-01 11:28:47' AND `subscription_valid_upto` = '2020-01-01 11:28:47'
WHERE `device_type` = 'I' AND `subscribe_at` = '0000-00-00 00:00:00' AND subscription_valid_upto = '0000-00-00 00:00:00'

Which works without errors but nothing happens , i have checked warnings and it says

Truncated incorrect DOUBLE value: '2020-01-01 11:28:47'

Here is my Table Data and its Structure.

Any help will be appreciated. Thanks.

UPDATE users 
SET subscribe_at = CASE WHEN subscribe_at = '0000-00-00 00:00:00'
                        THEN '2020-01-01 11:28:47'
                        ELSE subscribe_at
                        END, 
    subscription_valid_upto = CASE WHEN subscription_valid_upto = '0000-00-00 00:00:00'
                                   THEN '2020-01-01 11:28:47'
                                   ELSE subscription_valid_upto 
                                   END
WHERE device_type = 'I' 
  AND (    subscribe_at = '0000-00-00 00:00:00' 
        OR subscription_valid_upto = '0000-00-00 00:00:00' )