SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3dc81efeaf129824e76d9b362f17fb77d18bbe11b63641f460695097f8870849' 
  AND token = 'MfiocT+ZPxtdPXzgZD+fiwePYjqBBLDlEb0rBsBaUfY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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