SELECT 
  q_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      q_products_categories.link_type = "M", 
      CONCAT(
        q_products_categories.category_id, 
        "M"
      ), 
      q_products_categories.category_id
    )
  ) AS category_ids, 
  product_position_source.position AS position 
FROM 
  q_products_categories 
  INNER JOIN q_categories ON q_categories.category_id = q_products_categories.category_id 
  AND (
    q_categories.usergroup_ids = '' 
    OR FIND_IN_SET(0, q_categories.usergroup_ids) 
    OR FIND_IN_SET(1, q_categories.usergroup_ids)
  ) 
  AND q_categories.status IN ('A', 'H') 
  LEFT JOIN q_products_categories AS product_position_source ON q_products_categories.product_id = product_position_source.product_id 
  AND product_position_source.category_id = 383 
WHERE 
  q_products_categories.product_id IN (
    14849, 14850, 14851, 14852, 14853, 14855, 
    14858, 14860, 14861, 14862, 14875, 
    14880, 14881, 14894, 14933, 15229, 
    15284, 15285, 15288, 15519, 15712, 
    15713, 15726, 15772, 15778, 15837, 
    15866, 15867, 15868, 15872
  ) 
GROUP BY 
  q_products_categories.product_id

Query time 0.00109

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "151.61"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "q_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 32,
            "rows_produced_per_join": 32,
            "filtered": "100.00",
            "index_condition": "(`portal`.`q_products_categories`.`product_id` in (14849,14850,14851,14852,14853,14855,14858,14860,14861,14862,14875,14880,14881,14894,14933,15229,15284,15285,15288,15519,15712,15713,15726,15772,15778,15837,15866,15867,15868,15872))",
            "cost_info": {
              "read_cost": "68.41",
              "eval_cost": "6.40",
              "prefix_cost": "74.81",
              "data_read_per_join": "512"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ]
          }
        },
        {
          "table": {
            "table_name": "product_position_source",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "pt"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id",
              "product_id"
            ],
            "key_length": "6",
            "ref": [
              "const",
              "portal.q_products_categories.product_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 32,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "32.00",
              "eval_cost": "6.40",
              "prefix_cost": "113.21",
              "data_read_per_join": "512"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        },
        {
          "table": {
            "table_name": "q_categories",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "portal.q_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 6,
            "filtered": "20.00",
            "cost_info": {
              "read_cost": "32.00",
              "eval_cost": "1.28",
              "prefix_cost": "151.61",
              "data_read_per_join": "16K"
            },
            "used_columns": [
              "category_id",
              "usergroup_ids",
              "status"
            ],
            "attached_condition": "(((`portal`.`q_categories`.`usergroup_ids` = '') or find_in_set(0,`portal`.`q_categories`.`usergroup_ids`) or find_in_set(1,`portal`.`q_categories`.`usergroup_ids`)) and (`portal`.`q_categories`.`status` in ('A','H')))"
          }
        }
      ]
    }
  }
}

Result

product_id category_ids position
14849 383M 0
14850 383M 0
14851 383M 0
14852 383M 0
14853 383M 0
14855 383M 0
14858 383M 0
14860 561M
14861 561M
14862 561M
14875 383M 0
14880 383M 0
14881 383M 0
14894 561M
14933 402M
15229 383M 0
15284 383M 0
15285 383M 0
15288 402M
15519 383M 0
15712 402M
15713 402M
15726 402M
15772 383M 0
15778 402M
15837 402M
15866 561M
15867 402M
15868 402M
15872 383M 0