SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'd75107ff72ab08e09289be6fd18379e05d20bf8a989cdf2b56d5e793cd8cee39' 
  AND token = 'l/qAlAyWkwEFEzk2X/tg4XMY1JVC8ws2sVV2L6aXMQQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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