SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f101f62e94892d300edc67faae59d00120f3993af20df9c8f720db476d74e33c' 
  AND token = 'wMGGUyKdYKnExp8wXsiAiDdEvmIlIW5PqeUV+vEjbOk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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