SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cdc9ab851c29d450037e779f2574f4733f169fd9a6ca9881e798679f193408fa' 
  AND token = 'tcT3/1yGLHfC7k3LOrwPMQuFnGeEG51ES8pUC6Mvm88=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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