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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43d78925cc86c98a17a90282e92d44e22a46510b96b09485519db158ee401e7d' 
  AND token = '8uXgTBBTQ0xNY3dsu2WYO0rqsDttfWLYSfWqlwxQfzg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

Explain
id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
1	SIMPLE								Impossible WHERE noticed after reading const tables