SELECT 
  hv.hsycval_mode 
FROM 
  cscart_hubspot_obj_syncing_settings AS hs 
  LEFT JOIN cscart_hubspot_obj_syn_settings_value AS hv ON hv.hsycval_hsyncid = hs.hsync_id 
WHERE 
  hs.hsync_name = 'Order' 
  AND hv.hsycval_companyid = 1

Query time 0.00082

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "4.50"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "hs",
          "access_type": "ALL",
          "possible_keys": [
            "PRIMARY"
          ],
          "rows_examined_per_scan": 4,
          "rows_produced_per_join": 1,
          "filtered": "25.00",
          "cost_info": {
            "read_cost": "0.55",
            "eval_cost": "0.10",
            "prefix_cost": "0.65",
            "data_read_per_join": "216"
          },
          "used_columns": [
            "hsync_id",
            "hsync_name"
          ],
          "attached_condition": "(`poscentr_upgrade422`.`hs`.`hsync_name` = 'Order')"
        }
      },
      {
        "table": {
          "table_name": "hv",
          "access_type": "ALL",
          "rows_examined_per_scan": 36,
          "rows_produced_per_join": 0,
          "filtered": "2.78",
          "using_join_buffer": "hash join",
          "cost_info": {
            "read_cost": "3.49",
            "eval_cost": "0.10",
            "prefix_cost": "4.50",
            "data_read_per_join": "231"
          },
          "used_columns": [
            "hsycval_companyid",
            "hsycval_hsyncid",
            "hsycval_mode"
          ],
          "attached_condition": "((`poscentr_upgrade422`.`hv`.`hsycval_hsyncid` = `poscentr_upgrade422`.`hs`.`hsync_id`) and (`poscentr_upgrade422`.`hv`.`hsycval_companyid` = 1))"
        }
      }
    ]
  }
}