SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a74f1ab5145bfd402c13d602dc2c586f12c263e77e277e0f2bc9aa83e120857f' 
  AND token = 'rMg06u2vxA4UK0IJAgVg+UhMEzPxkThfF6oVxH7EFvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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