SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cd670b2b434ad0efea27e6effca34739d43ba959ae3a2db4e947c8a6d1359c62' 
  AND token = 'knP+/hBUVKacnubgzqml9eQBwCWwoJlFf1Pd0JAoWAg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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