SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92385b46249441f9e5af8c59ff984eb46b877b99e49f21201ef7be9b4ed6f808' 
  AND token = 'aseg+zueHtg+yjdynsd3lJQ+QDf+W6XoF7ikJ5/1GZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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