SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06f649b6dbbad11026268ffb79688c548e3ba4e27d589caaadddae4372c58faa' 
  AND token = '4WIfJR3X39iZlSayUA2tdZeChxVm96pRHseVIxfnW2M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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