SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b5ab140f00bf7a6e987ef4e5a579a1c8466ed71f2bb8db681daae23b6b3788c' 
  AND token = 'UR9p3eEQkGlIQbpub4kxMo/ws2p+KNdZgB1cEy/0DQk=' 
  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"
    }
  }
}