SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '599162f10c743a597a33a199726927a03e212618be1d5058d85d7b9a34e8180a' 
  AND token = 'F51psUvUDCpQ2KzBlMFmz7n//aNUj/Vh+Ad0O+hLFyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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