SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '46be28d1c901406355b851d85a2ac622c3168f79e31f0920eb5107ae231da5bb' 
  AND token = '2XNP1zNN0qG1VVgGz3PaHoScJeJ2RJoMhzUAqYnOCKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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