SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac79027867af997ec1d7a2e1fd864068654eafbc31c8aa31dc62460f124a7745' 
  AND token = '4f7bd+W/U+AMB3ffFxyWJNlP7CzieCOkbRk2sC+3s8M=' 
  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