SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fba0c9fea0b3b249bcdc195c82dc3f06d05b157d711205ea1003bed8f4eb9243' 
  AND token = 'YfmlSEBnpkzx9jGJv13t1AylyvZombz+NPvyuWaGP9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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