SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ab1f2fb3ab8b7bc1834e1e940a34bae67eb293e5637f2bdc84323769a0673c0' 
  AND token = 'SOfdxFfzgRszGXKA1ZFhm/qQQlxuhTed5pWwC6WY/vA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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