SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cb8d6bf798659a3647c6910ca5c8b440959f108c92ea98c4043292ab7d6e9571' 
  AND token = '7GGgIlJFuCxFVsk3K+CNN0X7srG2E/cx1m1BECJq0ZI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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