SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b50da105171f96a3ddb023d245a82b34ad6648b8ea8c03fe663db7f645c35785' 
  AND token = 'f/yzq2GY2FnN3jNJZXoGjA4/nqVc+W5WJF/h32nwWJc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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