SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dac4fc50dd3bc6def3f2645f370295f081a98d13406477953ab44b10163c6a18' 
  AND token = 'EY+D83mgp+Jk+mzwUJK5jDtz+M3iddO1OR3r3nE8xfw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

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