SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'ebcc2d642024d83ea5be10f0860bfa4c84a46d8232ca7fa2820971f26ede6086' 
  AND token = 'Win2YV8HJBZnFwYHDOa3NCSuINoOH+o1LDRXBWjd2EI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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