SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '08b8492b863aee8713f187c0ca43cb88f75e2f59784834b9ca30b8ce11e4d527' 
  AND token = 'fNxckl9G9QxDhmujzPZnWWrJYtbvdZ0OSbpb6BJzHtY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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