SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fb633f4d5cdf88fa9fafb9b47a8d3c933ecb14c91a3b262316e07db984c124e1' 
  AND token = 'cPclvVshCDBFIkFbW6wrDXyA7uxotCY2Tj/E/MsvFGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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