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 
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') 
WHERE 
  cscart_products_categories.product_id IN (
    461262, 461261, 461263, 461264, 461265, 
    461266, 461267, 461268, 461269, 460948, 
    461036, 461270, 230, 170, 227, 461033, 
    461242, 190, 461277, 312414, 325, 460946, 
    312456, 391037, 391032, 391031, 391030, 
    460955, 242, 243, 241, 240, 460947, 
    288, 214, 217, 218, 207, 312926, 199, 
    198, 201, 391002, 390979, 390978, 460951, 
    114, 192, 391013, 312901, 391014, 390986, 
    312443, 111835, 111837, 112217, 116529, 
    116541, 116547, 391009, 131, 177, 186, 
    185, 179, 400923, 400937, 400971, 391023, 
    22384, 312928, 312930, 312931, 312929, 
    312409, 312417, 172, 312421, 390994, 
    312424, 312425, 312426, 312427, 312428, 
    312429, 312430, 312431, 312432, 312433, 
    195, 233, 312854, 312855, 312864, 312852, 
    312853
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.00120

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.365479454,
    "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"],
          "loops": 1,
          "rows": 122,
          "cost": 0.17669501,
          "filtered": 100,
          "attached_condition": "cscart_products_categories.product_id in (461262,461261,461263,461264,461265,461266,461267,461268,461269,460948,461036,461270,230,170,227,461033,461242,190,461277,312414,325,460946,312456,391037,391032,391031,391030,460955,242,243,241,240,460947,288,214,217,218,207,312926,199,198,201,391002,390979,390978,460951,114,192,391013,312901,391014,390986,312443,111835,111837,112217,116529,116541,116547,391009,131,177,186,185,179,400923,400937,400971,391023,22384,312928,312930,312931,312929,312409,312417,172,312421,390994,312424,312425,312426,312427,312428,312429,312430,312431,312432,312433,195,233,312854,312855,312864,312852,312853)",
          "using_index": true
        }
      },
      {
        "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": ["u985510652_ecartify.cscart_products_categories.category_id"],
          "loops": 122,
          "rows": 1,
          "cost": 0.10994088,
          "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')"
        }
      }
    ]
  }
}