SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddec73cb3a47cc54818edaf1038d2af21b869558087b96492776af85d48463c7' 
  AND token = 'UFBpmgTMP8R9dX6cAFmNMpy3GvALvqbmtsQDE02sRgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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