SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee937df34a97688fa86334181f8d2ebf5045219a0bf8bebf037046740a112759' 
  AND token = '23o4KwudgT8glU+nMXvmjXKhTRey4wepo9vWlXUUs2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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