SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2f48248ef60efed2579361ce340b74cfd51313d315479ee3e7d0c2366a55c1e6' 
  AND token = 'eUQJFxifGHCE/REAXirvYgRScNt2HUA40qvKm/0mDcs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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