SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0276415bd9083447dd4882d839b9124ee5a091bb597e7e5fdb24b113eeed35d3' 
  AND token = 'YcvOziwPkIkNMJN56Jtr6bZrfN+Xo9gPQxJYTwDGCLg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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