SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4e4db08c70dcb44e3539f4aea1bbbda63c60153ee3213fa35970e1c1661f347b' 
  AND token = '6DOFVY98TvjyNTf9O562Va411T8ixr67xdHFT9txI5o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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