SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbd53270cc5ade038a080b97f7c469e6f5f78097e461fe6f56b7f9314ae30167' 
  AND token = 'HFmFlzBAuVJhjqryoNXkV3nIn2ny1ghZbnalUxmDTLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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