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 = 'ja' 
  LEFT JOIN cscart_vendor_plans p ON p.plan_id = cscart_companies.plan_id 
WHERE 
  cscart_companies.company_id IN('3') 
ORDER BY 
  cscart_companies.company_id asc 
LIMIT 
  0, 1

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "const_condition": "1",
    "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
    }
  }
}