SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2191288e1b20728725fde47a4407b78546fb3563a8409db788acc8b914a94ea3' 
  AND token = 'ug07IHP/wU/pE9hqZLDs1tr9ewV16qvwwWFMJgGWHdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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