SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3addc4f1ccf03fef20f016fa7c384833ee3300b0ee4de141e1c6c50329a5b147' 
  AND token = 'EqoWNI+M9WUUynX+g3xk2NnSBRVrwPGYk35pHc7z7u0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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