SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8094d6c74c7a477ceea019e85c28b37015b4ab1ee03ad76869c9808109ea21b8' 
  AND token = 'NtfWaurMogg/C6mezSgJw8h4k96mluMeTq3YIrmIcFU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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