SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f703fcf5cc29e32a03e2f76de4ba367f5dfad4eac9311e673531923b3e3101e7' 
  AND token = 'YD9FMMXyAzDQY1boykJYrWzz8llAj3nVUPYE7iUtg3A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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