SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '66d54f6a6356e71e09e54332a8a80502a55bf8b329a52a48e732ef1fdc1760f6' 
  AND token = 'gTbwHEDCTg8hoymZ4ghE8NXCuRtVDfjWDLsNxGJ/Yys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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