SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6fa3466a8e839d79c442b2a5d7a4f4f9a8128bdee3d78cbb7b7c2bfcab177416' 
  AND token = 'KweTgZ0vdS0tzH0gzaQRcEaS/inydKnlXVoBNgsUUrI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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