SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c814aaf440a9ad1323ea6d71bfaf651d5185fb5e66ffb9df65570ecf94f3a948' 
  AND token = 'bY4o/ojEq8HU+fYaW2WgRVELUoa1hfrlf8xh5F78z74=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00064

JSON explain

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