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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a5083646a2aac467daaa8143f6d92f0ef46345ca9d2313357944ccafbaf4ad2' 
  AND token = 'HYQb9rEy39ShLVHacufUkPnIYO3yKDuQUYuNSk9Hjx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

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