SELECT 
  cscart_company_descriptions.*, 
  cscart_companies.*, 
  p.price, 
  p.periodicity, 
  p.commission, 
  p.products_limit, 
  p.revenue_limit, 
  p.vendor_store, 
  p.categories, 
  p.storefronts 
FROM 
  cscart_companies 
  LEFT JOIN cscart_company_descriptions ON cscart_company_descriptions.company_id = cscart_companies.company_id 
  AND cscart_company_descriptions.lang_code = 'ru' 
  LEFT JOIN cscart_vendor_plans p ON p.plan_id = cscart_companies.plan_id 
WHERE 
  cscart_companies.company_id IN('7') 
ORDER BY 
  cscart_companies.company_id asc 
LIMIT 
  0, 1

Query time 0.02136

JSON explain

{
  "query_block": {
    "select_id": 1,
    "const_condition": "1",
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_companies",
          "access_type": "const",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "4",
          "used_key_parts": ["company_id"],
          "ref": ["const"],
          "rows": 1,
          "filtered": 100
        }
      },
      {
        "table": {
          "table_name": "cscart_company_descriptions",
          "access_type": "const",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "10",
          "used_key_parts": ["company_id", "lang_code"],
          "ref": ["const", "const"],
          "rows": 1,
          "filtered": 100
        }
      },
      {
        "table": {
          "table_name": "p",
          "access_type": "const",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "4",
          "used_key_parts": ["plan_id"],
          "ref": ["const"],
          "rows": 1,
          "filtered": 100
        }
      }
    ]
  }
}