SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '056c05919ba1b526e7d534d3fe2606cf383d460fcd28c08f05f35b64c5f0f3da' 
  AND token = 'ZJFpfyz+wp8sOEdYV9qn5mDzOlrENlt+jigXjZB31UY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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