SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'db0efc0655bc25b41879a1fec01dfdd68ada1eb9229a5ae54a30cc14edd7afa4' 
  AND token = 'snTx646IdErXTKasRIi0U9+vgGkM5zfT0rsQmJ15CyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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