SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '23bcca16970bdf6856e0c2482d3767550edbcfea621bf4f8ec8dff88b04f36ff' 
  AND token = 'bM7al51f4HpnKu+1tzSumHF+pKBwwC4R+FzJmVEGQtY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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