SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7da5ee72db0ce84b921a59d7e6e4b157188a8f3f581688dfd1de4f37faa48f4' 
  AND token = 'pWRBYc9ivtawhwEVa+K7kgxvOXC+DIej3VoG/iCnOvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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