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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe0fc8e55b3ab181ed14ae35f15e98c75747e9bcd67e8b90a90a315c7bf57314' 
  AND token = 'vMTFU1iFthPcpJk8NRHZEfL83QOg9/7FKV3M09U+gCE=' 
  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