SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3373bdd540eb6936196add8d6a87e923ce7fdf5bad28ae6792fc67a8dfc2190f' 
  AND token = 'wJirn4T9/IR5oUoW8SyuapvKzYqfH06OwziIhoddam8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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