SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '439f8138aa16d7191f31e5393760da082c0598d40e6e4dc1989f1ce53ea9526f' 
  AND token = 'Zvwt0ks009oomli7OwJsRhjzUvWvxD/9wdZLo87tbU8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}