SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9409504b16679db9ebc8761f47ce65cba1cce7586b589af1eea32f1f8e8c2702' 
  AND token = 'qG61RpoYKyCr8BOz7sjN0GlyIrV4w+6wuyYeW3H1Jlg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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