SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '895b1f8ec8d230927c82f16d27d664125fd4493e70fb34da7bc67f1bd1fb9ebf' 
  AND token = 'b9xBLJsYipMQNpBHuCEGRnnL6p4FstF2nNjXyZpnPW0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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