SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '75bf247d570174debad60e559e63e755e1b4222877b5a34201c83a8fdf53fb58' 
  AND token = 'zXw9VCAFxy0PXWCkkm4JvXLOFkfDqKdWuJ44Ni9iY6U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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