SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '578859e8a7b1f0746106fbbeafe51cf0ce54be35da01483456a881aab7cc6dad' 
  AND token = 'XPQbptq6w5eWhsgZv3XE1X8TdfWIgtl34PcmdEl44Ac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}