SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '192cf95818c31e8211b5fe64afbf0b46a3a20cc02799156a38b6c37ef1dc5122' 
  AND token = 'mvYiL7/2oocd5M50EjRCQ/d5fDoyRS0/Mist7bFdsk4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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