SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4f0876369c5b5587d71b8d9c436878bde825292cbbf6b90d48b2ea8256482978' 
  AND token = 'Mv2Na8D/DnblLTQLdH47fZvZY93/tZxsafNf/x4pwGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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