SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e40003392c6044a9c1b136f3896f51eaf00f3a5c298efed59bcda9d06e4a3a7' 
  AND token = 'Lhi/WbrzzfoAw5aoxrczY2JR6xOR8jw7qNFrFw+hs8c=' 
  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