SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b511d68e841573d0cb676851ca1def9a0ab680f8d882e3ebc8de2071a9a32785' 
  AND token = 'NrpfxZd0RtKSZ4Gj1a23yjZSHEfAqXaD6yMQgbCj0sk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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