SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '35f7fce053afc455bcbd560a3b797e0519887d7882ec4bdfbf4716c49d14db41' 
  AND token = 'aJAMG3J68LPOaXjWDpXXr8nEOGuXstdMt19jKoltUW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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