SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77da5f652d9b083869beac7212147894df8eb364412ee548f04542195327c2e5' 
  AND token = 'rcUhVzDAwGpM8EgfVpwW4Q8TUombr69LBLSX4ZG3fGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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