SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df48b838e1177e83ae8d532ce351928f36faccbe67d0d09c943ac12d88fcc32f' 
  AND token = 'HhNYHjGQmQykLdhCzR+3BCFtKUjyIeFhCanrySWqeUM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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