SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aee2dc28c1c702339c4afe08b55bdc1e5b46ad4b41fe027fe3f5c673ef00a2c4' 
  AND token = 'g8gUPnBwGbt+AzFcCjntTT1YfpbRbL162ekiIPHPmO0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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