SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b94cd29215c3aa2ae00edff54143dfd4d097151e3cfea242339bba79c8496ee' 
  AND token = 'cpGht3bU4D70CnyuNbkPhRP3dInT+XdRcqm91oU0jVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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