SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '73a0f78c3a340006300db803609fb5c5db99b4444a8f60013232a6d7f564f5ff' 
  AND token = 'khWdDpqk9lvc3pl0JzWWwEATj4W4Q9b11WeREQKUnr8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00061

JSON explain

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