SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'cd4e66855642edde941fd8af0875f7ce817bbb81dce1a425e39d01d4bb7771e0' 
  AND token = 'Ma7Qg+cE4WDqyZYbEP8DlgdmOrhEkva0giLxgj/3HgU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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