SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f68ba8fc5bbf1720b8f2cd8dd4488a76288178a19c85d97bfdb2ee45161f7c3' 
  AND token = 'FiOM8EPyUA6C7EMS/ajS/5q3q7Utf02oM4XI2mYr0LY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}