SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a67a27f69717362c870287e1cb7f27e9a3023b98b88a665e30448a901415d2b' 
  AND token = 'peecUv4xQWAMIwqdVSwL6JSsFnRzHjC+urehX5mW+ec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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