SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '157937247501d0bad1f2dfe795f3c8f8b774a7d9ff5d8e5042f502fffc00de7b' 
  AND token = 'jJFKz+4HCIz193drzJ/QfLPJKkxIYhoUYlDXuH6dIng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}