SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdcc8648c552192a3801064e53812a50838945f16142219af38cd277f8e91e3b' 
  AND token = '4PSvDRwQYLxtQ/o6yiSd/V8RxCh6R5Y6HIqpCdxuXaA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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