SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '418d4ea8e31cffdb5aa96cc43dbdad66dfb3b53c97fd3f425b0a7c4f0ce91931' 
  AND token = 'obKrSTKPJQMHn5xqXehnKvNYFUh2IRPrLAdW6asU18s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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