SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dac1afb747b2588e5e14412fb5a2cc69038349760a52a1138af055113aaaeaa4' 
  AND token = 'myDs5S0HViadT9KCg9gTbULLDocvREv62fsJg344oio=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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