SELECT 
  category_id, 
  parent_id 
FROM 
  cscart_categories 
WHERE 
  parent_id IN(
    9832, 3104, 3105, 3557, 3535, 3540, 3532, 
    2910, 5637, 9697
  )

Query time 0.00097

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "62.32"
    },
    "table": {
      "table_name": "cscart_categories",
      "access_type": "range",
      "possible_keys": [
        "parent"
      ],
      "key": "parent",
      "used_key_parts": [
        "parent_id"
      ],
      "key_length": "3",
      "rows_examined_per_scan": 153,
      "rows_produced_per_join": 153,
      "filtered": "100.00",
      "using_index": true,
      "cost_info": {
        "read_cost": "31.72",
        "eval_cost": "30.60",
        "prefix_cost": "62.32",
        "data_read_per_join": "907K"
      },
      "used_columns": [
        "category_id",
        "parent_id"
      ],
      "attached_condition": "(`webmarco`.`cscart_categories`.`parent_id` in (9832,3104,3105,3557,3535,3540,3532,2910,5637,9697))"
    }
  }
}

Result

category_id parent_id
2912 2910
2913 2910
2914 2910
2915 2910
2916 2910
2920 2910
2921 2910
2933 2910
2944 2910
3006 2910
3007 2910
3011 2910
3018 2910
3080 2910
3105 2910
3251 2910
3362 2910
3408 2910
3691 2910
4029 2910
5522 2910
3120 3104
3121 3104
3122 3104
3123 3104
3124 3104
3125 3104
3126 3104
3127 3104
3128 3104
3129 3104
3130 3104
3131 3104
3132 3104
3133 3104
3134 3104
3135 3104
3136 3104
3137 3104
3104 3105
3110 3105
3111 3105
3112 3105
3113 3105
3114 3105
3222 3105
3223 3105
3224 3105
3225 3105
3226 3105
3227 3105
3228 3105
3229 3105
3230 3105
3231 3105
3269 3105
9020 3105
9832 3105
3535 3532
3540 3532
3591 3532
9367 3532
9414 3532
9533 3532
3539 3535
3546 3535
3548 3535
3604 3535
3607 3535
3610 3535
3612 3535
3617 3535
3619 3535
3625 3535
3626 3535
3677 3535
3806 3535
3940 3535
3947 3535
4810 3535
5637 3535
6501 3535
6583 3535
9529 3535
3557 3540
3674 3540
3676 3540
3679 3540
3684 3540
3686 3540
3690 3540
3694 3540
3699 3540
3704 3540
3713 3540
3720 3540
3736 3540
3746 3540
3752 3540
3563 3557
3593 3557
3598 3557
3611 3557
3615 3557
3622 3557
3672 3557
5677 5637
5746 5637
5787 5637
5844 5637
5892 5637
5952 5637
6055 5637
6201 5637
6272 5637
6430 5637
9698 9697
9701 9697
9714 9697
9717 9697
9720 9697
9723 9697
9724 9697
9734 9697
9737 9697
9745 9697
9746 9697
9747 9697
9751 9697
9755 9697
9756 9697
9759 9697
9826 9697
9827 9697
9828 9697
9829 9697
9850 9697
9852 9697
9853 9697
9854 9697
9870 9697
9871 9697
9879 9697
9880 9697
9888 9697
9889 9697
9890 9697
9892 9697
9900 9697
9904 9697
9907 9697
9947 9697
9962 9832