SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09463dda74ca4105e8c70264d39d4d71d5d7dc5e169ef7487daa243079d912dc' 
  AND token = 'AzPh5zQQRjFIHatOGpggn+waqWcSLkgDq+MBuU+0odw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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