SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '386bdede0834a21263cba47cd991cfb10bb86d8b1dc4914d6c93f6e1739adf12' 
  AND token = '77V5zxlWMqvDhk5IJlCzxxHRe6P1URj3zH6X4FeR/2Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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