SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a64a09589b22af3054c96921a3a001dda98ad9ed85eb64ef17135e96191489ba' 
  AND token = '5wfI40hd0WnTSoAPHt6H9m23gq+msrc0som1vJF7iVM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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