SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1f34b3d686a05b93f7006b7620c734c83023db5eff623d7f934c08d5d9389fca' 
  AND token = 'Z7JhuH7iIJw/zHZI4mnCSbCiE46ADKreRa9h9xw+P4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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