SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '87f8de6ed78fd4fb5fdf669f227c429cf262a8e9a08f83299ed5f7de272e5a19' 
  AND token = 'I4uT9MlNE73QYIwcB+Ij2BJPyZUffuuNi771muc13yk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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