SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b81efd1ea1999d98c400e8d4914d28f58994805a73c7100a17725eda1c8a6028' 
  AND token = 'xexeVXddb4vdf3VJOFrAm61SMyP0oWicOHHlqXlIrM8=' 
  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"
    }
  }
}