SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2e3a5f60ec3f52471eea7109e33efd687b1b485f74b6792f1c83c0790b6dc096' 
  AND token = 'oBrmqKVRQUr46yZjcxpB7+TzQi3FxGy5xmrckhVLw4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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