SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'b17717cffbfb72fbbc483a15919ec7775e21f03b8d3e964acf0caef3828c3597' 
  AND token = 'Ri+DPCkD2Hpr/6kcnponzl4mgmYhWY2QEmeOgc/WkrQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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