SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '068b20ffea209a4ec4c2271033270c024d85cf51e6a6621a6cd74563669b48f8' 
  AND token = 'ZzGmP+KZ4jDB6/89W2n25SQ0c0xdpnSXXdO08OoGLdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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