SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'edda7d0af6c87fb047e6e86c8c5f48bd4006732b95a196e8b4f6d8099291a180' 
  AND token = 'mx4ZTpTTvC+XDQ08gaeg1kv4sc9cLuwiEIbUqVI3YqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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