SELECT 
  lang.name, 
  IF(
    cscart_ult_language_values.value IS NULL, 
    lang.value, cscart_ult_language_values.value
  ) as value 
FROM 
  cscart_language_values lang 
  LEFT JOIN cscart_ult_language_values ON cscart_ult_language_values.name = lang.name 
  AND company_id = 1 
  AND cscart_ult_language_values.lang_code = lang.lang_code 
WHERE 
  lang.lang_code = 'en' 
  AND lang.name IN (
    'text_gift_cert_amount_alert', 'recipients_name', 
    'purchasers_name', 'amount', 'gift_comment', 
    'text_no_products_defined', 'gift_add_products', 
    'how_to_send', 'send_via_email', 
    'send_via_postal_mail', 'gift_certificates.recipient_email', 
    'template', 'address', 'city', 'country', 
    'select_country', 'state', 'select_state', 
    'zip_postal_code', 'preview', 'purchase_gift_certificate', 
    'gift_certificate', 'text_gift_cert_amount_alert', 
    'recipients_name', 'purchasers_name', 
    'amount', 'gift_comment', 'text_no_products_defined', 
    'gift_add_products', 'how_to_send', 
    'send_via_email', 'send_via_postal_mail', 
    'gift_certificates.recipient_email', 
    'template', 'address', 'city', 'country', 
    'select_country', 'state', 'select_state', 
    'zip_postal_code', 'preview', 'purchase_gift_certificate', 
    'gift_certificate'
  )

Query time 0.00140

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_ult_language_values",
      "access_type": "system",
      "possible_keys": ["PRIMARY"],
      "rows": 0,
      "filtered": 0,
      "const_row_not_found": true
    },
    "table": {
      "table_name": "lang",
      "access_type": "range",
      "possible_keys": ["PRIMARY"],
      "key": "PRIMARY",
      "key_length": "392",
      "used_key_parts": ["lang_code", "name"],
      "rows": 22,
      "filtered": 100,
      "index_condition": "lang.lang_code = 'en' and lang.`name` in ('text_gift_cert_amount_alert','recipients_name','purchasers_name','amount','gift_comment','text_no_products_defined','gift_add_products','how_to_send','send_via_email','send_via_postal_mail','gift_certificates.recipient_email','template','address','city','country','select_country','state','select_state','zip_postal_code','preview','purchase_gift_certificate','gift_certificate','text_gift_cert_amount_alert','recipients_name','purchasers_name','amount','gift_comment','text_no_products_defined','gift_add_products','how_to_send','send_via_email','send_via_postal_mail','gift_certificates.recipient_email','template','address','city','country','select_country','state','select_state','zip_postal_code','preview','purchase_gift_certificate','gift_certificate')"
    }
  }
}