SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbc3ff47a8341651a969c1846fd97d70921cb605c0513245ff362e4467ffab0f' 
  AND token = 'LukiVvF3uCKWwuk/4WxpJ3dP1a5G5OOzwHLQs32utCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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