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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '74abb8aeb461af5280af08db8f38d02c2af22062878d3866e7b4fc0d82db5ad6' 
  AND token = 'paNJFraK6R7YjsRYMgWHPeXuWwI9onIL1IZGAxVCXIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

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