SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'febbd62e5ae3b4b16777ac6fcb32649efa19d4460bf7f6e905af03b70f53349f' 
  AND token = '7WpXmPFgVkbOD3FmBid3ZQapTzVE264aVnZCulpOD8s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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