SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3cdab32ba82226f10f1cf2b03fd5ab6bf93c1816e14698563e33afaa0b3a6354' 
  AND token = 'sYMBlBTz/JfGMbhgp8syI0HUkd8s0gnWnRbUkzY9d50=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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