SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fc0d1b48820c11ca9d4067c2e546c50dc6a571d782b57aeade4472caf57f209f' 
  AND token = 'ao0hLusie3+le6hb7ZFh5jF95K6mEcf0300tgJlPQJo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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