SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a64c97bef1c398f075ec30e24381b6c3e79796b3aa72ed702d081f77187c41d' 
  AND token = 'jhd6EufFsCSz3l17nJA/2t6UVIznVEHM2bTf3WjHNNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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