SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f681198c30b56cc1bf2d71161cf6b91a989cd01a4d715891086b4bd81826dbf' 
  AND token = 'BwStXkPFrTDef3YsqwiVL5loYcnLAHz7o7If0fpWlco=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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