SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4da3778dc8da5bf858607d2ce50ff250f87ed6c734b27630279fe15d8b32e546' 
  AND token = 'T+mtaJBB39yQSkOinYYECMGfjnpYP/BDawDKsQLYICo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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