SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '5ab2a325af1b4bb235028ee74f706a8585d107c65a257d61cc0a50ab6222c3b5' 
  AND token = 'dB+VkNIWccf+JYF4Z3DRv8DhbJhMJxAdx1Sm/LUBegY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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