SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '72de2a70903e7f69697fef2504dcb573a0cca068cb5fdafde3ce0ff9ad97649c' 
  AND token = 'YUIWqYD7EDBRvnvWsarZjdgN+yE3cg6roqz7+ILA9es=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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