SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e169925fcfcdab1887524b9296f78607027813023c02fbeb575f71f3d8cf4a57' 
  AND token = 'h5qRWKp+OdzKmYO/VIZrwuvJ2igeFqBv/Q+hK8wRp0g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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