SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '06208eaef28ee60e7966d6a354e9b4736b182341a7caff6c6a5dbfee05d6d809' 
  AND token = 'Z2MMuloHhpkZQt4MARNe1WDOKHkkWKBVO+45rNNgxpw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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