SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f0ea85cdbccc959a56a0158746f764d228a26076b246b7c28d1ec870c4219742' 
  AND token = '5fRDTJhualsQK7YFkiA32lZlB/6/DWspkyPXchRUYsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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