SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31e0d656eef8876a50ffd357b12f76fb608f03c6a7be01605987776328ce574c' 
  AND token = 'ZhUBm/TS6Ki44hFLWt/sVTHRlikIMjLCDD8+HcpgH1s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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