SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '81beb0c7a67323dda07cc00857ce06321d842a0a6052430dc78da58481aa5565' 
  AND token = 'RAzo6pgRXbQ3ZnJ5jyEFG8L7yH/7n//8OTJzGDqrJjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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