SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6bdfd6792973a0e71389fee9ce638f768722367f153b9cdaf0154138efa8f4d' 
  AND token = 'ZW17V8vSl8nud2L4XUsa3YkbSG9MQWiwAtIkCZ+SJaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}