SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6369d3d08eee3add35d351d17f3fbd7314ae7ebd0aee4449c9680a5401013b18' 
  AND token = 'vmzvMe51sTdgUimjou4yxiP5fDAG7G/ppsmCsn5v5UE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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