SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ccf955139a4a8e5a36fa21bb72143355d1bb3d9a0698ac2b896d57722bd0299' 
  AND token = 'S8QpHFCEBh7NIltsBoAFuHU7LwiU0oziWguG+I2wtu4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}