SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '855d173cdb1bf92dbfae7834fdbd1131d227ba7595332a9407112c1744225993' 
  AND token = 'fPXvpnVy5eh+tmhoAdQKEuw8VPPAaLeTtuS/O4Uu1/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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