SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '21cf1b3e00d992b9662ad0d73ef04558d06c4009cf86730aae8e4360c81ff2f5' 
  AND token = 'EJtraBR3vpQkdziztNe3c/RxFvf5LfSjZUiJMM1hIyY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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