SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67be2113e3229c8b5a12ffb3fc3578cc574b41e44bb7c43e924d8ef156367846' 
  AND token = 'mEAB2IqJ2QNRvQAJhZPlYttol2ymHfs0Ga/W3h7TUMQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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