SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '934e0f500d2e34c0778184a01f3d428938ed539503454e14e4183f9c676dc010' 
  AND token = 'SjPqbu+fyXpXPfRM95GfL0juYALDdzXJU/ielFgJsw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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