SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'af8a589b994f040beb768934694282b1329b8025033150f80ee2a0c133ea35cc' 
  AND token = '1ACYQynFKUyTWzZ6wd+Z/S6R+2jRtU1a7CHThpjC0d8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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