SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75ceaa9493ffdb63a6fbca28226cdd14603d41bd87c4be5ffe639b771a56eda6' 
  AND token = 'KSuQJOK1l29ax+mTiKGGvljjN0jPHTkXQzpeTTN3MIc=' 
  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"
    }
  }
}