SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56f14613e4f3b496d4fea982a622758d607164ceeb83feed3c2f9951c292edc8' 
  AND token = 'ZaqlwxUaGJYNfpYF8DtOFh4r72dy22mr1h5CBqnXO78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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