SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7beff071cc6cd6ce4fa0e5ac4f352aac6596639a831263c1be41ffe5f6948f56' 
  AND token = 'L5+eqsh6TEejuLD2SvFkUFb15sisLTcXO5Y6vrapb5Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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