SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31e221cbaf2368a69d63fdedace3edd5a52e60c9df7b7bab777001c7ca3974ee' 
  AND token = 'jVDEn6hgPiFclkCgLher4GqfaaWeaeg8lJIS7yCFUqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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