SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '119b6706f2b2314f14261780e5a9f6f47055e4530b18bd56251a093e3bb2a4b6' 
  AND token = 'l24Ig6MO933Z195QYfPAwUlRjJBVw5tDsEEpoM/g6ds=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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