SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '419e3cd0691a5cde36ecd89a95ff06c9e63ed85251b9550a051cd13d94a79dc7' 
  AND token = 'rFuSddy4kk9Qtd8FNCw7yZN0qwwcfUOVgRNIGc72QS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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