SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '43e94d0327387dfe5c41904bff7181f05debc4b4fb2ca7de4bac0c9814cebb81' 
  AND token = 'RX/NDHPo0zzty4rK4beKJpJiCuUdF293pSxuG/rbUOY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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