SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c854231dd24f031ce95321ad815329add375bae136f7b804d024347b2ba80f3' 
  AND token = '1SMeVk0hhGgepSM57jmjmtYHKpSPsxSjJUUaak9Th8k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

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