SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c19796152ce110de07a6a1f76c2f71f16ef4cb00f56cf038e7b36127cb67dc47' 
  AND token = '/0+AKrI5ntRyuoAzPgtJj4zJIuMsbMODzo7T9Man5qE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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