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 = 7165 
WHERE 
  cscart_products_categories.product_id IN (
    95551, 95552, 95553, 95554, 95557, 95683, 
    95702, 95703, 95944, 96177, 96178, 
    96179, 96180, 96181, 96182, 96183, 
    96184, 96185, 96186, 96187, 96188, 
    96190, 96191, 96192, 96193, 96194, 
    96778, 96779, 96780, 96781, 96782, 
    96783, 96784, 96785, 96786, 96787, 
    96791, 96792, 96793, 96794, 96795, 
    96796, 96797, 96798, 96799, 96800, 
    96801, 96802, 96803, 96804, 96805, 
    96806, 96807, 96808, 96809, 96810, 
    96811, 96812, 96813, 96814, 96815, 
    96816, 96817, 96818, 96819, 96820, 
    96821, 96822, 96823, 96824, 96825, 
    96826, 96827, 96828, 96829, 96830, 
    96831, 96832, 96833, 96834, 96835, 
    96836, 96837, 96838, 96839, 96840, 
    96841, 96848, 96849, 96850, 96851, 
    96852, 96853, 96854, 96855, 96856
  ) 
GROUP BY 
  cscart_products_categories.product_id

Query time 0.01781

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "102.90"
    },
    "grouping_operation": {
      "using_filesort": false,
      "nested_loop": [
        {
          "table": {
            "table_name": "cscart_products_categories",
            "access_type": "range",
            "possible_keys": [
              "PRIMARY",
              "link_type",
              "pt"
            ],
            "key": "pt",
            "used_key_parts": [
              "product_id"
            ],
            "key_length": "3",
            "rows_examined_per_scan": 114,
            "rows_produced_per_join": 114,
            "filtered": "100.00",
            "using_index": true,
            "cost_info": {
              "read_cost": "11.70",
              "eval_cost": "11.40",
              "prefix_cost": "23.10",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "link_type"
            ],
            "attached_condition": "(`nuie_scalesta_net`.`cscart_products_categories`.`product_id` in (95551,95552,95553,95554,95557,95683,95702,95703,95944,96177,96178,96179,96180,96181,96182,96183,96184,96185,96186,96187,96188,96190,96191,96192,96193,96194,96778,96779,96780,96781,96782,96783,96784,96785,96786,96787,96791,96792,96793,96794,96795,96796,96797,96798,96799,96800,96801,96802,96803,96804,96805,96806,96807,96808,96809,96810,96811,96812,96813,96814,96815,96816,96817,96818,96819,96820,96821,96822,96823,96824,96825,96826,96827,96828,96829,96830,96831,96832,96833,96834,96835,96836,96837,96838,96839,96840,96841,96848,96849,96850,96851,96852,96853,96854,96855,96856))"
          }
        },
        {
          "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",
              "nuie_scalesta_net.cscart_products_categories.product_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 114,
            "filtered": "100.00",
            "cost_info": {
              "read_cost": "28.50",
              "eval_cost": "11.40",
              "prefix_cost": "63.00",
              "data_read_per_join": "1K"
            },
            "used_columns": [
              "product_id",
              "category_id",
              "position"
            ]
          }
        },
        {
          "table": {
            "table_name": "cscart_categories",
            "access_type": "eq_ref",
            "possible_keys": [
              "PRIMARY",
              "c_status",
              "p_category_id"
            ],
            "key": "PRIMARY",
            "used_key_parts": [
              "category_id"
            ],
            "key_length": "3",
            "ref": [
              "nuie_scalesta_net.cscart_products_categories.category_id"
            ],
            "rows_examined_per_scan": 1,
            "rows_produced_per_join": 5,
            "filtered": "5.00",
            "cost_info": {
              "read_cost": "28.50",
              "eval_cost": "0.57",
              "prefix_cost": "102.90",
              "data_read_per_join": "14K"
            },
            "used_columns": [
              "category_id",
              "usergroup_ids",
              "status",
              "storefront_id"
            ],
            "attached_condition": "((`nuie_scalesta_net`.`cscart_categories`.`storefront_id` in (0,1)) and ((`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids` = '') or (0 <> find_in_set(0,`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids`)) or (0 <> find_in_set(1,`nuie_scalesta_net`.`cscart_categories`.`usergroup_ids`))) and (`nuie_scalesta_net`.`cscart_categories`.`status` in ('A','H')))"
          }
        }
      ]
    }
  }
}