SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5cbd5198585bbbc4f4da479b94cc2ed7f1d8dd428837f1dc03c329c1b34c6569' 
  AND token = 'pYdIu5Rc9ZbHivExybLtx3k/GM/1RBi7hDRKCR+z/zg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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