SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd56e05d9950b15ddc724afb5c9054910ca638996dfc8dbd1f502ce4e1e3a46cc' 
  AND token = 'M99SdnzEdhRttGIoj+pi23uaIcDlqd7jA9gNa5y8axk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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