SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fa1d8d22300bc721d66054b1d79a2509dcfc259cd0c3ba976091f5b65ddc589d' 
  AND token = 'Z3uTXfWe9a8MSkaIqiJG29pYJs/0xuhHtZoFjwNo7F0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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