SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '52c547124d93afe31fe9914e4d8e8791c477711400ad857b80e84659ecf4cbb0' 
  AND token = 'UxiHaGRRLsvyL9KtmNovM3cYyJ8Nu8zIGV7wpyXfSPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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