SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '52b9964ea4c9f5694af7864ee9feb8593bd95249db6db57b23f19864539543f0' 
  AND token = 'WOUDbgx2ZrLhh6KBbmsMetzCdUYYUwvIVfzYVN4iAVY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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