SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '499c4a312ad6bfa9be7e7cc27e833dae7abe42c37af5be178f0303c7838eb5c3' 
  AND token = '6TNULAdSj5+oTFvQOLAlHfVJPgok4tZWEUn4n7F3CKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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