SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '00fbe30e26bcbb5060b72ca5ec2082716df25f4653291f47bce91e2cec7ee78f' 
  AND token = '/ytWoWT+crTfDusGb+syvQssFWwMTutDbQtevhpXwrM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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