SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '98bbd5605a9f546efee9eaa845a78e62eb39aa97a97145f372a0478ccd3ff372' 
  AND token = 'm5yd1c8LxEnjhvNdv7m5WEcKvdkN4gEFK6ZWh/BZsi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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