SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '303fb7c08c37aca9e50927eebb952da2889c3dd51128442da2feda5ce853eaf1' 
  AND token = 'ohC0/0PRhRjpuQfC3ubkJVFnsUwWqUhRsoENv/MqwxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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