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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cc374977f439e194f8f2f575302fb5c64da5e35578a86d429d37a404e6aed5b' 
  AND token = 'CugANTcHb1CcuV79VWfSe+doDU/NhG4WHkBrkn3Fqfc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

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