SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48c23ccf973f35bd0ab4246f937eea51ff08d9970f7a8638063b3080e6787060' 
  AND token = 'nRC0035y8vz0HvkKOqVG2b2UoOEFhsf6O8sUWMgOviQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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