SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73cfc5c674242cfbd81ce85bf61dcc96785f227ddc6b3f0216f918fa53cceb06' 
  AND token = 'vk5HTEPudKsTh/G/ySmlmsJaj64p3qmQTW61ufvAfGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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