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 = 286 
WHERE 
  cscart_products_categories.product_id IN (
    10246, 10247, 10248, 10249, 10250, 10251, 
    10252, 10253, 10254, 10255, 10256, 
    10257, 10258, 10259, 10260, 10261, 
    10425, 10426, 10427, 10428, 10429, 
    10430, 10431, 10432, 10433, 10434, 
    10435, 10436, 10437, 10438, 10439, 
    10440, 10441, 10442, 10443, 10444, 
    10522, 9803, 9805, 9797, 9800, 9799, 
    9798, 9801, 9802, 9806, 9804, 9809, 
    9810, 9811, 9812, 9807, 9808, 9905, 
    10168, 10041, 10643, 10606, 10094, 
    10097, 12703, 10177, 10175, 9813
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00670

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_products_categories",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "pt"],
      "key": "pt",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 64,
      "filtered": 100,
      "index_condition": "cscart_products_categories.product_id in (10246,10247,10248,10249,10250,10251,10252,10253,10254,10255,10256,10257,10258,10259,10260,10261,10425,10426,10427,10428,10429,10430,10431,10432,10433,10434,10435,10436,10437,10438,10439,10440,10441,10442,10443,10444,10522,9803,9805,9797,9800,9799,9798,9801,9802,9806,9804,9809,9810,9811,9812,9807,9808,9905,10168,10041,10643,10606,10094,10097,12703,10177,10175,9813)"
    },
    "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",
        "noframes_angrybeaver.cscart_products_categories.product_id"
      ],
      "rows": 1,
      "filtered": 100
    },
    "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": ["noframes_angrybeaver.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')"
    }
  }
}