SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b341e613cb6448c934a667aab21c4d022edaef2d5ae585e54d35712db992ee97' 
  AND token = 'sW6tCxRwqwHz6ldRonoW8UsPNwHCjPBL6jHJEgIqnWg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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