SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93e55a393be0a0164dac756ce1b2b996e8a95ecd8715da3e2e017c64456e36f2' 
  AND token = 'AqEZAjDFxGHPbGuJri3OJ4tmmLYwqKZ30l5+DhWMs8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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