SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '09598b71e8a6a811373a4a22a3607e34ca0406e4ac825cdb54c59cc3bc7c7c06' 
  AND token = 'kVwciioH7iVwqjpYmQ1FJGwmNbjiqSVPuoflUMrYlSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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