SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c5ff5adad9286e8a233a5dfb6ac81629687070d3f48d3262914f98596a3661c' 
  AND token = 'f5Pzex4tME4prwwmCFbNbwpNfOGp2c7nogZfifdrayU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}