SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = '4af0d8ebe6822d12305e81493ea046add664395930689202560172d97949f0af' 
  AND token = 'OAZjaxg/FXZyGnHgipTBnwvtMp37N+7tEuqpp2zLw+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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