SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6bc048cc601b7baa59410c609f6959a99770a612d487ccaa1d741f6f36b0a1d0' 
  AND token = '0MZbv7BGqGsdKVSJgxjX6zEohc9G9J/KUGV1XgELxCk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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