SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc47b166c607caa69a6422aeaa3f238710bb99d99dbcfadb0c538e1626c6770f' 
  AND token = 'BPKPqJpG+LlZmWY6a1mQjidI2/CwDssHbKzUsfdPCb8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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