SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd859ed0f6ed504f46dafe76043bc985eaa6ff9bef39e531f98506bae4f75ed1a' 
  AND token = '6pO9hD8dC0ZSUg5tLF5jXltXVt8CUsgVgleKRDviv/A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}