SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3e0caa7027d8a86d26357b14519a044acfed0aa551e07fac547f18b3174d391f' 
  AND token = 'W1gg5zXu8G6A+DJzaYeD2UEp17VRQO4KOkFqzbvZZgs=' 
  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"
    }
  }
}