SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c02fac6c263e902bb8e51d2debbfd97bb88ce63e4120c773152ef1da38954ce1' 
  AND token = 'WgOT7iU5xI9gMVl9apmL192JT7xTvY7qcE4IehhHNNc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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