SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e78d83d639361057ddf0f059fc1fbbf3d8bbbba0ee251141c8cffad6d4d275ba' 
  AND token = 'eXYIgvWi0MVvwNKeyy0QllBgvoxK55oVtiPnBukSsNo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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