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SELECT 
  * 
FROM 
  cscart_product_feature_variants 
  LEFT JOIN cscart_product_feature_variant_descriptions ON cscart_product_feature_variant_descriptions.variant_id = cscart_product_feature_variants.variant_id 
  AND cscart_product_feature_variant_descriptions.lang_code = 'tr' 
WHERE 
  cscart_product_feature_variants.variant_id = 131

Query time 0.00010

Explain
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE	cscart_product_feature_variants	const	PRIMARY	PRIMARY	3	const	1
1	SIMPLE	cscart_product_feature_variant_descriptions	const	PRIMARY	PRIMARY	9	const,const	1

Result

variant_id	feature_id	url	color	position	variant	description	page_title	meta_keywords	meta_description	lang_code	gr__sf_seo_variant
131	18			0	Camelback	<p><p>CamelBak Products, LLC is an outdoors equipment company based in Petaluma, California, known primarily for its hydration products, such as hydration packs and water bottles. CamelBak is also a supplier of hydration packs, protective gear, and other products to the U.S. military and law enforcement agencies around the world.</p><p>The CamelBak name comes from a play on the myth that a camel stores water in its hump. In reality, those humps store fat.</p></p>				tr