SELECT 
  id_path 
FROM 
  cscart_categories 
WHERE 
  category_id IN (
    1593, 1768, 1804, 1852, 1856, 1926, 1930, 
    1934, 2002
  )

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_categories",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "p_category_id"],
      "key": "p_category_id",
      "key_length": "3",
      "used_key_parts": ["category_id"],
      "rows": 9,
      "filtered": 100,
      "index_condition": "cscart_categories.category_id in (1593,1768,1804,1852,1856,1926,1930,1934,2002)"
    }
  }
}

Result

id_path
1516/1529/1584/1593
1768
1842/1843/1804
1842/1849/1852
1842/1855/1856
1920/1921/1926
1920/1927/1930
1920/1933/1934
2002