SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9381103d2a9b93243052937499f3fc924095a1988b9765ddae7e14269eb1e9ef' 
  AND token = 'mVtNOPKJuasdmfS1HuQt6Ut2DoDaLCuEwB4LO4FWkGY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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