SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cd6b0e258d3ef97b4f86930626664ce7fb1ea0bf869bd157c93c14c151375826' 
  AND token = 'ld64xmyjtiD5MAKHishmsUHcHcuJ3yZTn0YrvUPkERg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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