SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f48742345ed25cf9905ef7bbd87828a6a318e1a742d91a9122533258e3e65089' 
  AND token = 'np7/HScYu4bkFHk5Y8mOXAYrAe+EweSgC+XdA6NVZCE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}