SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3b76cbb75f0e9ab20c3e9e2c36fc8fbde43daf840725ead1c8f724dfe3210b41' 
  AND token = 'nmIpygMR7/ATkDp3fcbJeQBJlGQMBscgGqZ96PNNIFM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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