SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da857f95fdd7f9f2db697e5b76552bcaa3e3e3dcffe320a386ba1bd6b2cdfcc9' 
  AND token = 'MG71ONSVB8wSWwuBZwxE1tOOrw8d0jhb6TkJ0etKgyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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