SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e03a36fcc766be74ff95338de3e983cfafbe2e334f701a718bf70ea343d146ad' 
  AND token = 'AKtl6saI6/VHPUF01TLnhxsO54CFbTS3WHocahgf1Ks=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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