SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b2564163dba351996ed8b91b6ce59dc9fad92520f6aeaa83f148a78b1335a0a' 
  AND token = 'tgYkVePdSd4oMMfWuUKhNd2x3bEc4N3QrVCoqbBjIeY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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