SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be5a12ba8afd477c3ce5e396b5a320ebbfd6fa2db752e1779e26fb3dc772b166' 
  AND token = 'NOmjsrJ/P2lv79HZBaTmrgwZ0vGxhMqI9hTK5jyIU64=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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