SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2b5ec83da58ca56257c0486c7d2c920a24f2446c3d42d3dc187f9ffd4f4c5428' 
  AND token = '76p1RiHGZIASw3QWP4HLSwqRazuy5dF+gGwLprW5gYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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