SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5a2787a4487bb1833c72774629ec68ec3858e2586a02bf8a0e962de974719bfd' 
  AND token = 'Op2Jj2aHdhOPVXRDBffni4SnkeQXBF5m/VOglywFCEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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