SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4e7df8214aa0b900a8429eaf34d35a8effc5743928a85c16377e752f702df1eb' 
  AND token = 'eghZJL9ww3ipl5H30zkqLKbrLAE+TOQgkTHuOpvKTz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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