SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '779153eeab064f3ac00c717db2016a396a735d3c8160222b656d115ec46a3d85' 
  AND token = 'vFhuIIv4e6jcDrxI45JwT/GKwNTfeHhDlZgvOXsZOQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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