SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'afa776cf9246d5c6c8c05fe56a6c9754fe9cc490e54bf36ce0ffa5798debb1d4' 
  AND token = 'Mdj56ftCjHPZguryyqrIpoEcv5URRsJcOhI41fhLfQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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