SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '589b5236538f8292e6d219becb3937a4de289d799aab194f532c118570075c41' 
  AND token = 'A1Aw5Fjq6c1LRJBfXV+aj3el/DXifZBle0Ely+4AkZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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