SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2499a056ad05866d560df29f1cf20f4b7ab52328393619dcc3a070e2b56d429b' 
  AND token = '6wNaHeVfSTC1jSsSzc/+Nbo3jhqRln7fbWxwpahtheI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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