Sandbox

SELECT 
  * 
FROM 
  cscart_bm_locations as l 
  LEFT JOIN cscart_bm_locations_descriptions as d ON d.location_id = l.location_id 
  AND d.lang_code = 'en' 
WHERE 
  l.layout_id = 2 
  AND l.dispatch IN ('categories.view') 
  AND (
    FIND_IN_SET(1, l.object_ids) 
    OR l.object_ids = ''
  ) 
ORDER BY 
  l.object_ids desc 
LIMIT 
  1

Query time 0.00017

Explain
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	l	ALL					90	Using where; Using filesort
1	SIMPLE	d	eq_ref	PRIMARY	PRIMARY	10	toolboxdigitalshop_dev.l.location_id,const	1	Using where

Result

location_id	dispatch	is_default	object_ids	layout_id	position	custom_html	lang_code	name	title	meta_description	meta_keywords
16	categories.view	0		2	40		en	Categories