SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85e00d495767c400d73fbc8d8f6fcecfc959e02d9ea0e10aa52e3f40eb34c9f6' 
  AND token = 'gCDLjdkWvFstBE4IyUHDRwgXjBF8nwYnso1EUa3NcC4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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