SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1036771b7fc1a6ad239758aee9163dbbd625d83832376e6518b6d07326263a54' 
  AND token = 'fxxoL3b1NFGgcboBAXWedbZIqZorKCh6qsb7USasXVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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