SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '203b16ab12cf1b60a16d94fa309a1471f00ebb1c4b2dd0881800ee10e105f71a' 
  AND token = '9o8VL6TnnoYlSWECQITkAGtzCiQyYmtKN60DFhGvFVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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