SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84469d00b398d17297966edc14a8556f253f2466d2fff9eb7b2404d7e9935546' 
  AND token = 'eo2JHasc9qPmczto33PfZgDBUCnzuQu5piKVYBS5uDk=' 
  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