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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '245dfeac8d1b28664283b3571d7e953016f845186fddeef2ff542dc5af5b725c' 
  AND token = 'OPwbtta40f+n3KBsTRC5Q9CkugtGKGTaox2kPVJyZVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

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