SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '028ec081e030de16454402e4367f9622e5607ff26f2010dfc423fb53d3f97950' 
  AND token = 'gJWYYgXS9yjYlJCbi0jHExHxuGC3gzjblT7ru8hLmGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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