SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43789f14de2f43973a0166d1f8e6fc5cb09f56af62596824526bd5539d8c8c41' 
  AND token = 'dUCix0weNHoK8SyQn/p6yBc3Z2w+Az4KhZvo8PQp9WA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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