How can I to search in mysql within a table of comma-separated values?

I have a MySQL table which contains comma-separated values like 2,4,56,125
and i want to search record which have a particular value.

so how can i search in mysql 

simple copy and paste this code in your table and change your table name and field name and search keyword.

SELECT * FROM table WHERE FIND_IN_SET(search_keyword , field_name) 

like

SELECT * FROM tbl_font WHERE FIND_IN_SET(2,cat_id)