SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '00be5989f3bbf9b749c00cb6351df8d62acfac4e5c935610af80e39a6b20b8de' 
  AND token = 'X2lya2FsWaHxq9Vl5wI8o5nHd0w+Jg/weBUi82AqqxA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}