SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9830008f5f3fd1cd5b5e36a3b1fcad0ca903806c07786936354f64aed32a9c3e' 
  AND token = 'jKJuz4EumeFK6BOZ767gKMhwIh4wK9S2ZTkQw0feoc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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