SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6577509ad77b822ac7a723136502bfb7927eaeda059dbd79241a63933797766f' 
  AND token = '8lYZMgBMS4XfDJUVd8+UWzCqamqRz3hSZRz7gOuu14g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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