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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b9882b3f82ad23e0bfec7581d0305d841fa4d494569bb30da917ee10bd8be58' 
  AND token = 'iPnBHe0QdEX0LirxH4EKq9qgB9nUeg7lciw4oTgtZIk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

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