SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7fa2b578e78334546c02e4ab88c19294db76e0de34ca68aa5e42252958997b49' 
  AND token = 'QpEAvILG+Ojh+xIfmps7fOmG5CjKsidgMlxrLWNbYUI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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