SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a935a8611fa89a255ad2b38e42ee289428a85641cc2ba19ef59080490c1ab9ad' 
  AND token = 'YJtXxoUQNpBnusZoChLkqTTn9lDd0GUxM6RLeMJnHew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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