SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc0769026b53dd0f21e5c62ce10184b33b74a7aebf4c17215640e1146234e979' 
  AND token = 'F7j7sFEFr5hq7k2ryNp+jJmBKvWNxqhgz9bHS5/MDZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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