SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e3984731696893381d242a8cf973aa4be0056ebbe9876873e4920d95315ccb1' 
  AND token = '29hSjCyK+H2ph39UqGtFZINtDdAKaZ97s3O9l9fwdKU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}