SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2bd65fe1dead1b35fc1d6fdbc309af65f5d9d85efb5b22460b1bb7d5c22ec7c0' 
  AND token = 'N+ZlCzC7prdkBQI1M0IHlBhVXwGXyzjsb/J3YwPnYSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}