SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba3afae34870fb504591ab187932dbdff8d3e59e1bf9fe59e01df5952eedad3e' 
  AND token = 'b9r2WJ37yvmCI2OntHWiukemY0bYLLwgPYPnwrIN38Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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