SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19253cb65b097ba99c17530e38b0ecddecc0c830f60b457d6b3c00b15481ab18' 
  AND token = 'YmdemuQ2G6TcoItQDizZQjl9ykQe0b7vsO/hzDMFOJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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