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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 = 120

Query time 0.00113

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
120	18			0	Arc System Works	<p><b>Arc System Works</b> is a video game developer and publisher based in Yokohama, Japan. It was founded by Minoru Kidooka in 1988. Arc System Works is best known for its arcade 2D fighting game, Guilty Gear and its sequels.<br></p>				tr