SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a769d3b5b123c046a6d26738a5c769f36952dca56b81fa6728c7cdc1eb7c5870' 
  AND token = '1JaWeOFH7reA+oQeCEUIu12SkYIc2bUWijnX1z9ykpU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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