SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df60bd0636bcb972f470c02f8106805d125e228ba3135eb703ca94a6ba412410' 
  AND token = '2TektPz74HdssR+68xZKuUCdqpu7OgYqvQLTY9CaOBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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