SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '246bf9b90d1ffd33523b4dbab576d7e60932f2343a4c43f9ffc9953af3ef4f47' 
  AND token = 'GVve6B3w8kCnNwuAMJncRUCXlSTbqzvJBwtF0YSOJKU=' 
  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"
    }
  }
}