SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6020939f903a28f3f3f666858c5c3837246ad2d03956578d31b9dc80922ea923' 
  AND token = 'wPt+mJAjj3GPz6fXGJ51abdGGPbqaMynKBDK/7bxRvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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