SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '501c74e9f1b799879bb2db2310e2c692bf16135b728c5fecb55a4c330f54c899' 
  AND token = 'vkZcfJ0AHGSozTpBVybycQXRfrURihY0vnqMGHYDJAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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