SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '708833dc48b4532e6a483896fec20dd6e3e39c5effe255372a3a5ab2bfabc69b' 
  AND token = 'wBQeMI+xWFrmE8J5YNRXO03aoLzpEvUWsgaRDIQryko=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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