SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7973962a25102357d55f66c3ff2ea379e2211c28f074ce5688017708e9811bee' 
  AND token = 'xbIgIhDMTVPvxsS3vZW6k4MzYzvLDxiZioE9erhyFTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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