SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c469b820adb8915964962e158a6e3f4493b57f4df99ec234413b33c0ad724785' 
  AND token = 'iPvb6J4Cteplfn6GMFsqdsfkUfdZzI4VsmE+DGdj5XE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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