SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc2bafccd893fabbfe3a1bde47213f553bbe7476c72b907185630a8a29b4ad14' 
  AND token = 'tlX5jYbE6zOQG7Zok+CC6j0HO0y3JVqe1Or+jRuO03E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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