SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd2fb2395a17578e058ef3e81b57085bd980746029c2fc12ae944762287b569e' 
  AND token = 'vwqs5X+MTDmOakrgTvL4wYW+mfz0b/fgr+4NMXqlHpI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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