SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '409e3751d74909f456394e546db0f79f8adf9efe5d5a94e81124c6e5fe113d55' 
  AND token = '9pBp5SgcsxMQ+Q6UFSUMdHeeTSoTcO5Dk2BD/tovahM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

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