SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '32bd8019f56e007436a22c5debc00eaba342c6ee8e356d38d686b8e32aa3e608' 
  AND token = 'oleYQ0qBMxy2SRpkz2MecYSb4+z4/PQb5/MTjOb1kIU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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