SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21efaf71363114631b823e67580690c35321f408032ae586f898cf810cb9915e' 
  AND token = 'd6e1jh/YBgamx/8szC3p/IOwmP+cP41CJHccQoSGkEA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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