SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b68c4301f96675dfe3d380dc124c6bfa090252f3100533532d8abe7714745cd' 
  AND token = '7AbmLM7sTPmzmYvA2Vkz20gJGd5uu6W6ZxWeLqRhZqk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

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