SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ea74ad40ffccfb2edd78791c82233e9ee9a15f29553d309f16131ef58e04fa73' 
  AND token = 'uDSElYP78ZIlWx1wlkWNfK3iICRykNlAGJY5m0XRitg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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