SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cd6d43c35b40f72f7b68fdb548a31f633f9253d41fdfac8d0fd88a12241bc008' 
  AND token = 'cELFmQuMr9uW3NIGzPaR6N1n2xGO8+KWCSbkYtIrpJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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