This type of date field in MySQL should be usable in the DataAssist Search server behavior to get back results.
To test it out try this, create a new page and add a recordset that will select all from this table that has the timestamp field. Once you have got the recordset crafted create the results display on the page and add the repeat region around it to show all of the records.
Next you will want to add a small form to the page, just something with an input and a submit button will do.
Now add in the DataAssist Search server behavior. In here configure the search to work on the time stamp column. For the criteria just choose date, for comparison choose less than, and for the type choose edit. For the Edit field name use the lightning bolt to select the text field of the form you just added. Double check the settings before clicking on ok.
When you test this you should be able to enter a valid date into the text field and have all of the records with a date that is previous to this show in the results. Please post back with what you get.