SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9241e08d487ad54fde69870aa3b500b6d14ae5547ae1575cffb70aa80b73abc7' 
  AND token = 'EZllrJbHOenZpVG+MKhfMaZoBMvj4gRHZC79uJ7E7zk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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