SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '47ddb9b36281ae49b12941df66087833a61640f193192242816dcf7b1bada588' 
  AND token = 'oVGPvwCB/Gn8Zx/bEEdhgAaFGdd7uRXxALvw2dtK4o8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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