SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8abb44124627e7fa27e0508b4411610e1f9c9b156867da84783943e8a9036033' 
  AND token = 'H8NYJ9QnfviZfrufA/AgduVzmkui+ms+qlxdezrxBv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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