SELECT 
  cscart_profile_fields.*, 
  cscart_profile_field_descriptions.description, 
  cscart_profile_fields.checkout_required as required 
FROM 
  cscart_profile_fields 
  LEFT JOIN cscart_profile_field_descriptions ON cscart_profile_field_descriptions.object_id = cscart_profile_fields.field_id 
  AND cscart_profile_field_descriptions.object_type = 'F' 
  AND lang_code = 'ja' 
  INNER JOIN cscart_ult_objects_sharing ON (
    cscart_ult_objects_sharing.share_object_id = cscart_profile_fields.field_id 
    AND cscart_ult_objects_sharing.share_company_id = 2 
    AND cscart_ult_objects_sharing.share_object_type = 'profile_fields'
  ) 
WHERE 
  1 = 1 
  AND cscart_profile_fields.profile_type = 'U' 
  AND cscart_profile_fields.checkout_show = 'Y' 
ORDER BY 
  cscart_profile_fields.position

Query time 0.00094

JSON explain

{
  "query_block": {
    "select_id": 1,
    "read_sorted_file": {
      "filesort": {
        "sort_key": "cscart_profile_fields.position",
        "table": {
          "table_name": "cscart_profile_fields",
          "access_type": "ALL",
          "possible_keys": ["PRIMARY", "checkout_show"],
          "rows": 24,
          "filtered": 83.33333588,
          "attached_condition": "cscart_profile_fields.profile_type = 'U' and cscart_profile_fields.checkout_show = 'Y'"
        }
      }
    },
    "table": {
      "table_name": "cscart_profile_field_descriptions",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "12",
      "used_key_parts": ["object_id", "object_type", "lang_code"],
      "ref": [
        "cscart_purchase_fl_com.cscart_profile_fields.field_id",
        "const",
        "const"
      ],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "trigcond(cscart_profile_field_descriptions.object_type = 'F' and cscart_profile_field_descriptions.lang_code = 'ja')"
    },
    "table": {
      "table_name": "cscart_ult_objects_sharing",
      "access_type": "eq_ref",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "159",
      "used_key_parts": [
        "share_object_id",
        "share_company_id",
        "share_object_type"
      ],
      "ref": [
        "cscart_purchase_fl_com.cscart_profile_fields.field_id",
        "const",
        "const"
      ],
      "rows": 1,
      "filtered": 100,
      "attached_condition": "cscart_ult_objects_sharing.share_object_id = cscart_profile_fields.field_id and cscart_ult_objects_sharing.share_object_type = 'profile_fields'",
      "using_index": true
    }
  }
}

Result

field_id field_name profile_show profile_required checkout_show checkout_required partner_show partner_required storefront_show field_type profile_type position is_default section matching_id class wrapper_class autocomplete_type description required
6 firstname Y N Y Y N N Y I U 10 Y C 0 first-name given-name Y
7 lastname Y N Y Y N N Y I U 20 Y C 0 last-name surname Y
8 company N N Y Y N N Y I U 30 Y C 0 company organization 会社名 Y
9 phone Y N Y Y N N Y P U 40 Y C 0 phone tel 電話番号 Y
32 email Y Y Y Y Y Y Y E U 50 Y C 0 litecheckout__field--full off E-mail Y
14 b_firstname Y Y Y Y N N Y I U 90 Y B 15 billing-first-name given-name Y
16 b_lastname Y Y Y Y N N Y I U 100 Y B 17 billing-last-name surname Y
30 b_phone N N Y Y N N Y P U 140 Y B 31 billing-phone tel 電話番号 Y
26 b_country N N Y N N N Y O U 150 Y B 27 billing-country country 国名 N
28 b_zipcode Y Y Y Y N N Y Z U 160 Y B 29 billing-zip-code litecheckout__field--xsmall postal-code 郵便番号 Y
24 b_state Y Y Y Y N N Y A U 170 Y B 25 billing-state state 都道府県 Y
22 b_city Y Y Y N N N Y I U 180 Y B 23 billing-city city 市区町村 N
18 b_address Y Y Y N N N Y I U 190 Y B 19 billing-address litecheckout__field--xlarge street-address 番地 N
20 b_address_2 Y N Y N N N Y I U 200 Y B 21 billing-address-line2 address-line2 ビル・建物名 N
27 s_country N N Y Y N N Y O U 270 Y S 26 shipping-country country 国名 Y
29 s_zipcode Y Y Y N N N Y Z U 280 Y S 28 shipping-zip-code litecheckout__field--xsmall shipping postal-code 郵便番号 N
25 s_state Y Y Y Y N N Y A U 290 Y S 24 shipping-state state 都道府県 Y
23 s_city Y Y Y Y N N Y I U 300 Y S 22 shipping-city city 市区町村 Y
19 s_address Y Y Y N N N Y I U 310 Y S 18 shipping-address litecheckout__field--xlarge shipping street-address 番地 N
21 s_address_2 Y N Y N N N Y I U 320 Y S 20 shipping-address-line2 address-line2 ビル・建物名 N