SELECT 
  cscart_products_categories.product_id, 
  GROUP_CONCAT(
    IF(
      cscart_products_categories.link_type = "M", 
      CONCAT(
        cscart_products_categories.category_id, 
        "M"
      ), 
      cscart_products_categories.category_id
    )
  ) AS category_ids, 
  product_position_source.position AS position 
FROM 
  cscart_products_categories 
  INNER JOIN cscart_categories ON cscart_categories.category_id = cscart_products_categories.category_id 
  AND cscart_categories.storefront_id IN (0, 1) 
  AND (
    cscart_categories.usergroup_ids = '' 
    OR FIND_IN_SET(
      0, cscart_categories.usergroup_ids
    ) 
    OR FIND_IN_SET(
      1, cscart_categories.usergroup_ids
    )
  ) 
  AND cscart_categories.status IN ('A', 'H') 
  LEFT JOIN cscart_products_categories AS product_position_source ON cscart_products_categories.product_id = product_position_source.product_id 
  AND product_position_source.category_id = 146 
WHERE 
  cscart_products_categories.product_id IN (
    22172, 2157, 38152, 47085, 38146, 38145, 
    3601, 286, 26467, 47148, 4389, 2163, 
    15613, 4393, 1850, 2626, 4392, 38150, 
    4394, 38141, 20830, 38148, 18274, 2159, 
    2162, 732, 38147, 1851, 2148, 1840, 
    1852, 2625
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00719

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_products_categories",
          "access_type": "range",
          "possible_keys": ["PRIMARY", "pt"],
          "key": "pt",
          "key_length": "3",
          "used_key_parts": ["product_id"],
          "rows": 51,
          "filtered": 100,
          "index_condition": "cscart_products_categories.product_id in (22172,2157,38152,47085,38146,38145,3601,286,26467,47148,4389,2163,15613,4393,1850,2626,4392,38150,4394,38141,20830,38148,18274,2159,2162,732,38147,1851,2148,1840,1852,2625)"
        }
      },
      {
        "table": {
          "table_name": "cscart_categories",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "c_status", "p_category_id"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["category_id"],
          "ref": ["dev_db.cscart_products_categories.category_id"],
          "rows": 1,
          "filtered": 100,
          "attached_condition": "cscart_categories.storefront_id in (0,1) and (cscart_categories.usergroup_ids = '' or find_in_set(0,cscart_categories.usergroup_ids) or find_in_set(1,cscart_categories.usergroup_ids)) and cscart_categories.`status` in ('A','H')"
        }
      },
      {
        "table": {
          "table_name": "product_position_source",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY", "pt"],
          "key": "PRIMARY",
          "key_length": "6",
          "used_key_parts": ["category_id", "product_id"],
          "ref": ["const", "dev_db.cscart_products_categories.product_id"],
          "rows": 1,
          "filtered": 100
        }
      }
    ]
  }
}

Result

product_id category_ids position
286 146M 0
732 210,146M 0
1840 146,318M 0
1850 146M 0
1851 210,146M 0
1852 210,146M 0
2148 210,146M 0
2157 210,146,318M 0
2159 146M 0
2162 146,318M 0
2163 146,318M 0
2625 146,210,318M 0
2626 146,318M 0
3601 146M 0
4389 146M 0
4392 146M 0
4393 146M 0
4394 146M 0
15613 146,318M 0
18274 146M 0
20830 146,210,318M 0
22172 146M 0
26467 146M 0
38141 146M 0
38145 146M 0
38146 210,146M 0
38147 146M 0
38148 146M 0
38150 146M 0
38152 146M 0
47085 210,146M 0
47148 146M 0