SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '07e0afc14a4c676ffe5329dd344b539a23a345207f97e66c9fdac5713c4eb9e8' 
  AND token = 'xWtqtlabj1AneEcl27MVSZjhBDALwKK1JEgvfLGJkjw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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