SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8866e776b4282a5c00734fef648c49f44c9358a40a520ddfdcc9edc870537eab' 
  AND token = 'gj/IlNhZN3nAyLcmSnqq5k8POHsWHdJXgGbDCwEsjpY=' 
  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"
    }
  }
}